Follow TV Tropes


Fanfic / The Arithmancer

Go To

Cedric: Alright, cool it, you two. She's a first year girl who just happens to be better at Arithmancy than…anyone Professor Vector has ever seen.

The Arithmancer by White Squirrel is a Harry Potter Alternate Universe Fanfic in which Hermione Granger is a mathematics prodigy instead of an all-around bookworm, leading to her testing into Arithmancy from first year, and later delving into spell-crafting. However, with her parents' greater involvement in the school as a result, they are more aware of the life-threatening circumstances that she keeps getting into each year, and they are not happy...

It is complete and covers Years 1-4, with a completed sequel, Lady Archimedes, covering Years 5-7. A third story, Annals of Arithmancy, which is set after graduation, was finished in March 2019.

Unmarked spoilers below.


    open/close all folders 

     # - K 
  • 90% of Your Brain: This turns out to be how the Diadem of Ravenclaw works. It allows the conscious mind full access to all the sensory information, processing power, and memories that the subconcious normally filters out. Normal people can't handle that level of input and overload, but Hermione has been training her entire life in the sort of mental discipline necessary to handle the Diadem.
  • Absurdly Sharp Blade: One of Hermione's early experiments in creating armaments based on carbon nanotubes is a stiletto sharp enough to literally split hairs, yet strong enough to slice through steak like a cleaver, with a tungsten core to give it heft. She makes a sheath from the same material, because nothing less would reliably contain it.
    Hermione: I christen thee... the Black Blade of Buckminsterfuller.
  • Accidental Kiss: Harry and Ginny's lips touch by accident when he's rescuing her from the Lake and sharing a Bubble-Head Charm with her. She has the presence of mind to linger for a moment.
  • Adaptational Badass: In addition to Hermione being such a math whiz, there is also Ron's chess skills, and the whole trio's, plus Professor Vector's, actions in the Chamber of Secrets.
  • Adaptational Skill: In the Arithmancer continuity, the Weasley siblings are able to speak French, having been taught this by their parents in case they had to move to France to escape the war and be educated at Beauxbatons. This gives Ron an increased interest in languages and hence skill in Ancient Runes, as Hermione persuades him to take the elective.
  • Adaptational Villainy: In Lady Archimedes, the author manages to pull this off with Umbridge — who was already a villain in the original novels, by having her release even more Educational Decrees than canon (a full list by the end of fifth year is available in the ending footnote of Chapter 29), show open Fantastic Racism to students in class, and actively do things that she only threatened to do (but got stopped) in canon, e.g. Crucioing a student and enforcing corporal punishment.
  • Adoptive Name Change: The son of Barty Crouch Jr and Bertha Jorkins, named Marvolo Crouch initially, is renamed 'Marcus Aurelius Vector' after being adopted by Septima Vector.
  • Adults Are Useless: Subverted with Hermione's parents who grow increasingly distrustful of Hogwarts' commitment to student safety with each passing year. After she is nearly kissed by a Dementor, the Grangers force her to transfer to Beauxbatons.
  • After-Action Healing Drama: The end of Chapter 67 to Chapter 69 of Lady Archimedes take place in the aftermath of the raid on Malfoy Manor, and primarily deal with several medical emergencies in the Weasley (extended) family that occurred either during or after the raid, and later, the Death Eater attack that ensues.
  • Alternate History: In this fic, the witch hunts began much earlier, as early as the 9th century.note  King Malcolm III didn't like that his predecessor was getting help from witches, and started an active persecution of witchcraft.
  • Alien Geometries: Hogwarts runs on this. Not only do the interior's measurements not match the outside, the corridors have different measurements across different floors. And parallel corridors in a rectangle aren't necessarily the same length, even after testing that they all meet at right angles.
  • Allohistorical Allusion:
    • One of Ginny's nightmares, after surviving being taken into the Chamber of Secrets, is of Harry getting bitten by the basilisk, after having to slay it alone because Hermione has been petrified and Ron has been blocked by a cave-in, just like what happened in canon... except without Fawkes saving him. Hermione gets a feeling that this is exactly what Harry would've done had he actually been in this situation.
    • After Hermione and George attend the Yule Ball together but decide not to try a long distance relationship, her next visit involves hugging Harry and Ginny and several other friends, then awkwardly pausing with George and mutually deciding to shake hands. (Note that this happened in the movies with Hermione and Ron, not the books.)
    • When Hermione, at the breakfast table, promises payback if Rita Skeeter is using illegal means to get her stories, one of the other girls states, "You know, you're scary sometimes, Hermione? Brilliant, but scary."
    • In the last chapter of Annals, a First Year student claims his older brother told him Hermione once "broke into Gringotts, stole a dragon, and rode it into battle".
    • When Ron asserts that even if Sirius Black sent Harry's new broom, it's still sacrilegious to strip down a Firebolt, Hermione internally thinks, "He needs to sort out his priorities."
  • Amazon Chaser: On multiple occasions, George makes remarks indicating that he finds Hermione's use of ingenious ways to defeat or incapacitate Death Eaters very attractive, though scary at times.
  • Anger Born of Worry: George to Hermione in Chapter 57 of Lady Archimedes when her insomnia-derived recklessness caused her to Apparate in front of the Weasleys' shop during a Death Eater attack and nearly get hit with a Killing Curse.
  • Animal Lover: Hermione, though she makes an exception for Dementors.
  • An Arm and a Leg:
    • Cedric survives the Third Triwizard Task by using a light-based spell to disrupt Barty Crouch Jr's vision, but quite literally loses an arm and a leg in the confrontation that ensues.
    • At the end of the Battle of Hogwarts, Blaise Zabini is seen alive but missing his left arm.
  • Armed with Canon: In-universe, and more literally than usual. Christian wizards and witches point out that the Bible only bans divination and necromancy.
  • As the Good Book Says...: As she studies soul magic in order to understand Horcruxes (including the one in Harry), Hermione purchases religious books in Chapter 64 of Lady Archimedes. She later "borrows" a Bible in Chapter 71 while on the run from the Death Eaters, and bases one of the de-Horcruxing rituals on a passage from the Book of Job. Oh, and she also makes emergency rations based on Manna — down to the taste, even — from natural resources (e.g. dirt and wood), and goes out of her way to make it fulfill the nutritional requirements to survive.
  • Ascended Extra: Professor Septima Vector, who takes a major role in Hermione's life as her Arithmancy teacher. They become close enough that she's involved when going after after the Philosopher's Stone, and the basilisk.
  • Attack on the Heart: Hermione's medical research leads her to develop a variation on the Sumerian Strike Hex, which is no more powerful than being punched in the nose — but her version delivers that force directly to the heart in a way designed to cause cardiac arrest. And it can penetrate single-layer shields. She almost kills Bellatrix Lestrange with it in the Battle of the Department of Mysteries, but another Death Eater, Rookwood, was smart enough to revive her.
  • Attention Deficit... Ooh, Shiny!: Played for Drama. In Lady Archimedes, Hermione when she's on the run from the Death Eaters. She has so many projects and problems facing her that she has a hard time focusing on the most important ones.
  • Awesomeness by Analysis: In Chapter 48 of The Arithmancer, Hermione casts the Bat-Bogey Hex without anyone actively teaching her via this.
    Ginny: (whirling on Hermione angrily, poking her in the chest) Hermione Granger! Did you go behind my back and convince Bill to teach you that spell?
    Hermione: No. (pushes Ginny's hand down) I just watched you cast it enough times that I was able to arithmantically reverse-engineer it.
    Ginny: You... you used arithmancy?
    Ron: (in awe) You figured out her spell just by watching it?
    Hermione: Yes. Mind you, it wasn't easy. It took quite a bit of sixth-year maths, but I did it.
    Ron: That's bloody brilliant!
  • Back for the Finale: After disappearing for most of 'seventh year', Rita Skeeter makes a comeback, having gathered a six-inch stack of parchment's worth of intel on the Muggle-Born Registration Commission for Hermione. This proves to be very useful since the Ministry's own records have partially been destroyed and are otherwise incomplete.
  • Badass Boast: There are a number throughout the series:
    • When Draco taunts her with the prospect of the Unforgivable Curses being legalised by Voldemort, she laughs at him.
      Hermione: Anyone who resorts to Unforgivable Curses doesn't have an ounce of creativity.
    • She's also fond of Archimedes' boast: Dos moi pa sto, kai tan gan kinaso.note 
    • When reassuring her parents that she can protect herself in Chapter 46 of Lady Archimedes, before they left for Australia:
      Hermione: Look, you two are dentists. People joke about how you can strike fear into the hearts of the strongest men. But I've been studying your old pathophysiology textbooks, and I have magic.
    • Most notably, in Chapter 47 of Lady Archimedes, Hermione snares a curse out of the air, deconstructs it while giving commentary, collapses it harmlessly, and follows this up with a direct reference to Galadriel's "All Shall Love Me And Despair" speech.
    • Another one shows up in Chapter 19 of Annals, when a Boggart turns into a Weeping Angel speculated to have all the powers of one (due to the creature's Assimilation Plot characteristics), and the students and teachers have to call in Hermione with Ministry backing to deal with it in fear a new 5-X magical creature was created.note 
      Hermione: I'm the Doctor. The Oncoming Storm. I've fought monsters and slain demons. I've made the very sky turn to darkness, and I will not suffer you to persist on this planet. You may call yourself an Angel, but I'm the Angel of Death... Fear me.
  • Badass Bookworm: In this Alternate Universe, Arithmancers tend to be this.
  • Badass Longcoat: Hermione is gifted one made of Basilisk skin, as thanks from a group of Indian cursebreakers who were saved by her protective glasses. Aside from looking awesome, it also has potent spell resistance.
  • Black Dude Dies First: Lee Jordan dies in the battle of the Department of Mysteries, making him the first character to die "onscreen".
  • Blinded by the Light: Remus and Sirius suggest fighting a dragon with a Conjunctivitis Curse, but Hermione is concerned about whether Harry will be able to reliably hit its eyes. So instead, she invents a spell to extract a cloud of magnesium powder from the soil, which he can then banish at the dragon and have it ignited by the dragon's breath for a colossal flashbang effect. He ends up using three clouds at once, and completely incapacitates the dragon.
  • Blood from the Mouth: The Hemorrhaging Curse, Dolohov's specialty, causes the victim's body to "dro[p] like a puppet whose strings had been cut" and start "coughing up what seem[s] to be an impossible amount of blood", and can kill in less than five minutes if it hits vulnerable places in the body, like the head or neck.
  • Blood Knight: Blaise Zabini, the only marked Death Eater to be considered innocent, joins the Reconciliation Committee established after the war. He's the most militant and bloodthirsty of all members, basically demanding the death penalty for all of the Death Eaters.
  • Body Horror: When Hermione begins devising curses, she starts by digging into her parents' medical textbooks. The results are horrific. And when Hermione is done with Umbridge, she's almost unrecognizable as anything but abstract art.
    Hermione: Epidermolysis bullosa!note 
  • Bread and Circuses: Hermione literally shouts "PANEM ET CIRCENSES!" during the first Triwizard Task, although only a few muggle-born students understand her social commentary.
  • Brick Joke: After Hermione gets sorted a third time, the Sorting Hat tells her that if she does "manage to appear before me a fourth time", she'd go to Slytherin. Years later, while going to Flitwick's office due to troubles her daughter caused, the Sorting Hat immediately shouts "Slytherin!" at her.
  • Broken Masquerade: A focus of the last few chapters of Annals of Arithmancy, Played for Drama. Hermione realizes that keeping up the Statute of Secrecy will soon become mathematically impossible due to the proliferation of Internet-connected cameras storing data on remote servers. She publishes her work, is immediately arrested for treason, and ultimately has to defend her conclusion in front of the International Confederation of Wizards.
  • Broken Pedestal: After Sturgis Podmore is Kissed, Hermione decides that although she's still on the same side as Dumbledore, she can no longer rely on his plans, and she starts making her own arrangements for her friends' safety.
  • Chekhov's Classroom: Ancient Runes class is surprisingly helpful at driving the plot, especially in The Arithmancer (as well as Lady Archimedes regarding the ritual to take down Voldemort).
    • In the first two years at Hogwarts, Professor Babbling teaches various younger students, this time including Harry, Ron, and Hermione, to carve runes into wooden blocks in seminars. This helps Hermione to create, with Ron's help, wandless potions kits that even muggles can use, using wood-block runes to provide the magic required for the brewing process. It is used again in Chapter 57, where Ron carves runes to be charged with fortification spells to delay Professor Lupin from breaking out of the Shrieking Shack as a transformed werewolf. This manages to hold until the group reaches Dumbledore for help.
    • Later in the book, Professor Babbling teaches the Bliviklet spell to her third-year class to link runes together in Chapter 53, explaining its practical application for simple and temporary defensive and monitoring systems. This comes in handy four chapters later, when Ron uses the spell to alert him and the rest of the group the moment werewolf-Lupin breaks out of the Shrieking Shack.
      Ron: Entwined pair of runes, remember? They're good for monitoring. When it breaks, we'll know Lupin got out.
  • Chekhov's Gun: In Year 2, Hermione brews Veritaserum instead of Polyjuice Potion to interrogate Draco Malfoy about the Heir of Slytherin. She keeps a small phial of it after the incident, and come Year 3, surprise! She has more than enough of it to interrogate Peter Pettigrew in the Shrieking Shack to help set the historical record straight.
  • Collection Sidequest: After the success of her magnesium extraction spell, Hermione tries her hand at collecting samples of each element (or in some cases, like sodium, simple compounds). The fact that she extracts them in powder form is an inconvenience, but she doesn't let it stop her, she just melts down the powder into an ingot, using homemade thermite for the tougher elements.
  • Compensating for Something: George makes a joke about this regarding Lucius Malfoy's eighteen-inch wand in Chapter 33 of Lady Archimedes.
  • Corporal Punishment: It was never formally banned at Hogwarts, but Dumbledore used his power to forbid it. Umbridge, however, brings it back when she becomes headmistress.
  • "Could Have Avoided This!" Plot: After the drama and danger of the fake Locket Horcrux, Hermione learns that Elf Apparition wasn't being blocked in the cave, meaning that Dobby could have transported them in and out. She is not amused.
  • Crazy-Prepared: After the war, Hermione has a big job on her hands emptying out everything from her extended handbag, from synthetic food to incomplete magic-infused runes to homemade guns to a collection of deadly poisons, nerve gas, and even chlorine trifluoride. And that's after she lost many of her possessions at Malfoy Manor.
    Hermione: C-4, C-4, more C-4. Why did I make so much C4?
  • Creator's Culture Carryover: A mild example; the use of 'Sincerely' to sign off a letter is a characteristic of American English, while British English uses 'Yours sincerely'.
  • Cut His Heart Out with a Spoon:
    • Hermione's dire threat that gets the bullies off of Luna's back is… if they keep it up, she'll sic the Weasley twins on them.
    • When the Twins later drag her to Madam Puddifoot's tea shop, Hermione threatens them that if rumours begin to circulate about the three of them being an item, she'll curse them so badly that people will be talking about that instead.
  • Day of the Jackboot: Voldemort takes over the Ministry in Chapter 47 of the Lady Archimedes, a few months earlier than canon due to Dumbledore's death.
  • De-power: Septima Vector loses her ability to do math, and thus use Arithmancy after she suffers traumatic brain injury due to being Crucioed.
  • Dead Guy Junior: As per canon, several of the extended Weasley family's children are named after their fallen family, friends and allies, including James Victor Potter (middle name for being born in early May, a couple of days after the anniversary of the Battle of Hogwarts) and William Kingsley Potter.
  • Death by Adaptation:
    • Lee Jordan dies in the Battle of the Department of Mysteries after being hit with Dolohov's signature Hemorrhaging Curse.
    • Cho Chang touches the cursed necklace in Chapter 41 of Lady Archimedes instead of Katie Bell, and dies instead of suffering Katie's canon nightmarish-but-curable torture. The author's notes later clarify that, while Katie in canon touched the necklace through a tiny hole in her glove, the character who touched the necklace in this fic wasn't wearing gloves at all, and suffered the full brunt of the curse chosen to assassinate Dumbledore.
    • Draco Malfoy gets nailed with a Shotgun Curse after killing Dumbledore.
    • Sybill Trelawney is killed after the Valentine's feast with Malfoy's poisoned bottle of mead.
    • Oliver Wood gets hit with a Killing Curse while acting as The Cavalry to evacuate a family with muggle-born children to France.
    • Either this trope or Dies Differently in Adaptation: Fenrir Greyback is beheaded with Snickersnack in the Death Eater attack on the University of Nottingham Hospital, while his canonical fate is ambiguous (either death or post-war imprisonment in Azkaban).
    • Bill and Great-Aunt Muriel also die in the Death Eater attack on the hospital.
    • Augustus Rookwood, Hermione's Evil Counterpart, is taken down in the Battle at Wellow with a magical machine gun she built, when he was only stunned and most likely sent to Azkaban after the war in canon.
    • Winky is revealed to be Killed Offscreen by Barty Crouch Jr in early autumn 1997, but she canonically survives the war.
    • The Battle of Hogwarts in particular goes quite differently than canon:
      • Terry Boot was listed as the first casualty of the Battle of Hogwarts when it was implied that he survived the war in canon.
      • Amycus Carrow was killed by Michael Corner early in the Battle, while he was most likely shipped off to Azkaban after the war in canon.
      • Kingsley Shacklebolt is killed by an invisible Death Eater. Hestia Jones retaliates by going on a small Roaring Rampage of Revenge and cursing the Death Eater in question to pieces.
      • Augusta Longbottom is killed by Rodolpus Lestrange with several dark curses, who is in turn killed by Luna in an Unstoppable Rage, with Rodolphus' body only described to be "lying on the floor, bloody" in the aftermath.
      • Xenophilius Lovegood was killed from unknown causes.
      • Lucius Malfoy is struck with a Heart-Stopping Curse, then has his chest caved in with a Bombarda to prevent any Death Eaters from reviving him.
      • Professor Sprout gets a Slashed Throat from a Death Eater, most likely Dolohov.
      • Seamus Finnegan is hit with a Killing Curse from Dolohov trying to protect Ron.
      • Parvati Patil has a knife thrown into her chest by Macnair.
      • Either this trope or Dies Differently in Adaptation: Antonin Dolohov is killed by the Weasley Twins with their prank products, when he is defeated by Professor Flitwick in canon with his fate (life/death) left ambiguous.
      • Rabastan Lestrange has his neck magically broken by Neville, with the intent to avenge his family.
      • Tracey Davis is hit with a curse from Pansy Parkinson that caused her to break her back on the staircase railing on a floor below, and then fall to the floor.
      • Pansy Parkinson is killed with "a flash of spells" in retaliation to Tracey's death, but it is unknown who actually killed her.note 
      • Professor Babbling, being affected from a Necrotising Curse from earlier chapters, dies as the curse spreads to her blood in the immediate aftermath of the ritual that killed Voldemort, as part of the "misfortune" price to pay for the ritual.
      • Tilly died to protect the younger students when the Death Eaters went for them after Voldemort's fall. In contrast, canon does not list (or perhaps have) any House Elf casualties.
      • Other identified minor/supporting characters who died in the Battle of Hogwarts of the fic continuity but either survived or had ambiguous fates in canon include Jimmy Peakes (reportedly eaten by Acromantulas), Sophie Roper (hit by a Killing Curse), Kevin Entwhistle (unknown causes), Hannah Abbot, Oliver Rivers, at least two more House Elves, and an unnamed First Year student.
      • Overall, 43 characters are stated to have died for the Light side in the Battle of Hogwarts, and a full list of named casualties are listed at the end of Chapter 81 of Lady Archimedes.
    • In the hunt for Barty Crouch Jr, Aberforth Dumbledore and Padma Patil die in the last skirmish, with the latter sacrificing herself to save Lavender Brown.
  • Death Is Cheap: By late 2001, ten percent of the Dementor-hunters in Britain have been Kissed at some point, even multiple times, but destroying the Dementor responsible releases the soul back to the body with no lasting effects.
  • Deconstruction Fic: Not the most extreme example, but the fic does point out certain inconsistencies in the characters' behavior, as well as the general weirdness of the wizarding world.
    • The first arc does a Decon-Recon Switch of the Chronic Hero Syndrome, pointing out that first years simply do not know enough magic to face a troll, which is defeated with a non-lethal One-Hit Kill spell cast by Professor Vector.
    • Kid Hero is deconstructed too, as everyone points out that a first year at Hogwarts would be curbstomped in a fight against an adult wizard and Harry's attempts to get to the Philosopher's Stone are seen as suicidal.
    • Later, the obstacles get an in-universe Difficulty Spike and Quirrelmort got through by cheating, using an obscure charm to make Vector's enchanted statues color-blind and causing a system failure that opens the doorway.
    • Hermione points out that Mandrakes are literally Person of Mass Destruction due to their lethal scream. If a malicious wizard put an amplifying charm on the plant it would result in the death of thousands. However, Professor Sprout points out that the lethal effects are not instantaneous and that the scream cannot be reproduced artificially, such as recording the scream. And that a silencing charm will render the mandrake harmless.
  • Despair Event Horizon: The Basilisk attacks on muggleborns have such an impact on Hermione that by Christmas she's ready to either give up magic altogether or be transferred to another school.
  • Determinator: Oh, Hermione, for sure. In the twenty-four hour span around the Battle of Hogwarts, she visits Somerset to destroy the Horcrux in Hufflepuff's Cup, duels several Death Eaters and shoots Rookwood, faces Voldemort, goes to Hogwarts to prepare for battle, plans and conducts a ritual to kill Voldemort once and for all, gets chased by Bellatrix Lestrange for an hour until sunrise such that her misfortune price from the ritual wears off, and fights Bellatrix in a duel intense enough to take down the Astronomy Tower and render Hogwarts Castle uninhabitable and ends the duel with killing Bellatrix.
  • Didn't Think This Through: In the summer before second year, the Dursleys decide that they will tell the wizarding world that Harry ran away. However, when McGonnagal comes to fetch Harry after Hermione express her worry, she quickly informs them that there are ways to track underage wizards, of which owls are one of them.
  • Dies Differently in Adaptation:
    • Dumbledore is hit by a Sectumsempra, as opposed to the Killing Curse. The circumstances related to his death also change accordingly — he's killed by Draco Malfoy in mid-December 1996 (on the 18th, to be accurate, or the 19th if post-midnight), as opposed to Severus Snape on 30 June 1997, though both occur in the aftermath of retrieving one of Voldemort's Horcruxes.
    • Mad-Eye Moody is killed during the infiltration of the Ministry of Magic, as a direct adaption of the Battle of the Seven Potters doesn't take place.
    • Peter Pettigrew is nailed with a Piercing Hex to the head by Harry in the Battle at the Hospital rather than being strangled by his silver hand. It probably helps that he doesn't have a silver hand in this continuity to begin with.
    • Severus Snape is hit in the back with the Killing Curse after revealing his allegiance by killing a Giant rather than getting bit by Nagini on Voldemort's orders.
    • Vincent Crabbe is stabbed through the chest by presumably a statue from the Great Tower, as there was no reason for our heroes to visit the Room of Requirement when they'd already cleaned the Diadem Horcrux out months before the Battle.
    • Voldemort is killed with a ritual instead of his own Killing Curse backfiring against him.
    • Bellatrix Lestrange is Eaten Alive by Hermione's creation, The Deplorable Word, instead of being killed by Molly Weasley by either an overpowered, literally heart-stopping Stunner (book) or being frozen in place and shattered to bits (film). She also dies after Voldemort does and not before.
    • Bertha Jorkins survives for a few years longer than canon but dies in the Battle of Hogwarts from unknown causes.
  • Disproportionate Retribution: Hermione considers Azkaban — full of soul-devouring demons that cause clinical depression by their mere presence — to be too harsh for Rita Skeeter's actions, and her parents agree. Rita is shocked by their attitude, but doesn't complain about getting a better deal.
  • Doorstopper: The first two books have over half a million words each.
  • Dramatic Irony:
    • Played for Laughs; Hermione's letter home after the troll incident includes the phrase "It's not like an evil psychopath sneaks in and tries to kill somebody every year or something." In canon, almost every book focused on exactly that.
    • When the Grangers hire Dobby, he stubbornly insists on living in the cupboard under the stairs, claiming it's better than what he's used to and convenient for keeping him out of sight of visitors.
    • Professor Vector comments that an elf who wants wages is so rare that it's not something people normally consider, like an evil Gryffindor or a cuddly werewolf. This is in the summer before third year, where Professor Lupin teaches at the school and Peter Pettigrew is exposed.
    • As in canon, during the boggart lesson, Lupin's fear is shown to be the moon. Anyone who read the original books or watched the movies knows that this is because he's a werewolf — but Hermione has no idea and just wonders why. She doesn't wonder for long, in fact, she figures it out the very next chapter.
  • The Dreaded:
  • Dream Reality Check: Daniel Granger pinches himself when Professor McGonagall transforms his table into a tortoise to prove that magic exists.
  • Driven by Envy: Rebecca Gamp, who comes from a long family of spellcrafters, towards Hermione. When Hermione is facing her worst breakdown, caused by the Existential Horror of Dementors, along with strained friendships with Harry and Ron due to Scabbers' disappearance, she makes snide comments to try to convince her to transfer to another school.
  • Easy Sex Change: Downplayed. It's briefly noted in Lady Archimedes that Metamorphmagi can change their biological sex as part of their power, but it is more difficult than normal appearance alteration (such that "they can't do it on a whim") and it doesn't affect the Metamorphmagus' gender identity.
  • Eaten Alive: Bellatrix Lestrange is basically nibbled to death by Hermione's Grey Goo backup weapon. It's a very unpleasant way to go.
  • Education Mama: Downplayed. The Grangers are distraught to find out that Hogwarts favors magic over science and muggle history, but when Professor McGonagall informs them that it's possible to hire tutors and that magical education is only compulsory up to fifth year, they back down. For the most part, they're the Open-Minded Parent.
  • Eldritch Abomination: The giant blob of dust and woodchips that appeared in the Battle of Hogwarts. Considering that it seemed to be the last thing to come down from the upper floors of the Grand Staircase, it was probably the top of the Grand Tower. But it was still animated by McGonagall's spell, and it still fought for Hogwarts.
  • Eldritch Location:
    • The upper floors of the Grand Staircase, as Hermione finds out. You can just keep climbing the stairs apparently indefinitely, finding more and more rooms, but they're increasingly wrong, containing incomplete objects, nonsensical angles, and disproportionately large or small spaces.
    • The Third Task takes the form of a tesseract maze, which is mathematically regular, but hard to observe and far enough outside normal experience to mess with viewers' heads. Professor Vector thinks that Hermione could have made something worse, but even as it is, her own spellwork disturbed her when it was done.
      Septima: You probably know all about four-dimensional geometry.
      Hermione: Not all about it, but enough. Be glad I didn't, though. If you set the champions loose inside the Grand Antiprism, they could get lost for weeks.
  • Establishing Character Moment: Dumbledore's first appearance in this fic is to notice that Harry has missed six of his Hogwarts welcome letters and seemingly not be bothered by this... but then he mentions that if this keeps up, he's going to send Hagrid to make sure Harry gets his letter. This is not one of the "evil incompetent manipulative Dumbledore" fanons; he might be a bit off-kilter, but he does know what he's doing and he does care about Harry's well-being. It's also clear from this scene that he's a bit of a troll; he frames his decision to send Hagrid as being because he thinks Hagrid will be happy to see Harry again, which anyone can imagine is true, but his grin as he says it makes it clear that he knows just how much a half-giant barging into their home to explain magic is going to unsettle the normalcy-obsessed Dursleys.
  • Evil Counterpart: Voldemort's traitor Unspeakable Augustus Rookwood is a spellcrafter almost as good as Hermione and can use a Pensieve to recreate her best work.
  • Exact Words: Hermione doesn't like lying, but freely makes use of misleading truths:
    • Dobby has been ordered to report to her parents when she's in a dangerous situation, as soon as she no longer needs his protection. When she doesn't want him to immediately report the World Cup attack to her parents, she is able to point out that by the time he's about to go, she's no longer in a dangerous situation, therefore the order doesn't have to apply.
    • As per canon, Dumbledore tries to stop her from giving Harry any sensitive information over the summer before fifth year. But what she actually promises to do is not to send any sensitive information that might be intercepted, and Dobby can deliver letters securely.
    • Harry gets in on it himself a bit later; after Ginny has him stage a fight with her over being Locked Out of the Loop and Mrs. Weasley is trying to convince him to "reconcile" with her, he tells her that he thought Ginny would at least send him a note (which he did), only to learn everyone was fine and Ginny simply hadn't written him (her communications had had to go through Hermione), and he thinks he has a right to be angry about it (he isn't angry, but he definitely thinks he has the right to be).
  • Existential Horror: Hermione does not cope well with learning about the Dementor's Kiss, and the accompanying idea that souls are real, but not necessarily immortal.
  • Explosive Results: Dobby is keen to help his new masters Granger, and tries to have breakfast ready when they wake up, but unfortunately they had not yet taught him how to use all their appliances, and his experimentation results in turning on all the jets of their gas stove. When he finally manages to trigger the starter, the resulting blast ignites the nearby cabinets and throws Dobby himself into the sink — luckily with nothing worse than a bruised head and singed clothing.
  • Eyebrows Burned Off:
    • The staff at Beauxbatons had never before seen the Potions lab's fire protections fail against non-magical fire, but then, they had never tried using thermite for high-temperature metallurgy, either. Hermione loses both eyebrows and basically scares off a boy who was interested in dating her.
    • She loses them again in her first attempt at splitting water into its hydrogen and oxygen components (but it worked!).
  • Failed Attempt at Drama: Hermione invents a magical blacklight spell for the Yule Ball, but doesn't remember until actually using it that it only makes clothes glow if they've been washed in fluorescent laundry detergent, and wizards don't have that. As a result, the effect is that only her dress glows (along with her and Harry's teeth, thanks to Muggle fluoride toothpaste), which is far less impressive than what she was going for.
  • Faking the Dead:
    • Hermione arranges for her parents to leave the country, then disguises herself as a Death Eater and stages an attack on their house, burning it to the ground and leaving behind two corpses with falsified identifying marks — to clarify, the cadavers were donated to the dental school for anatomical education, and Hermione obtained them through her parents' connections. She even convinces Snape to take the credit for it with Voldemort, so that there won't be an anomalous attack that no Death Eater admits to making.
    • After the attack on the Rookery—the Lovegood residence—at the end of sixth year, Xenophilius Lovegood escapes but fakes his death, later continuing to start the Voice of the Resistance Liberation newsletter anonymously under a different writing style.
  • Fantastic Firearms: When Hermione wants to test the resilience of her basilisk-skin coat, she rigs up a rune-lined pipe as a magical railgun, constantly accelerating a lead slug down its length. It’s not portable, but it gives her precise control of the muzzle velocity and is quiet enough to operate it in her basement without alerting the neighbours.
  • Fate Worse than Death:
    • Beyond their already bad canon characteristics, ghosts also can't grow mentally, trapped in whatever mental state they were in when they died, and cannot get new memories. Nearly Headless Nick speculates that they might be able to pass on if they stopped being afraid of death, but since they can't mentally or emotionally develop, that can't happen.
    • Canon briefly states that the Dementor's Kiss is worse than death, but doesn't explore the subject. Hermione, however, is deeply traumatised by learning about what it does, and doesn't start to recover until she resolves to learn the Patronus Charm so she can defend herself.
  • Faux Death: Introduced in Chapter 61 of Lady Archimedes, Hermione invents a spell that can suppress the victim's reticular activating systemnote  and put them in a deep coma, and can't be woken up with anything but the specific counter-curse. Its incantation is based on the original Grimms' fairy tale title for Sleeping Beauty.
    • After Yaxley and Runcorn follow the Order back to one of their bases-of-operations (via Apparition) following the infiltration of the Ministry, Hermione wipes their memories with a modified potion, then casts this spell on them in lieu of executing them (as that would be a war crime in the non-magical world).
      Kingsley: Even like this [under the spell], we'll still need the resources to keep him alive.
      Hermione: No, we won't. That's the other part of my plan. Draught of Living Death would look conspicuously odd to muggles, but his coma won't. We'll drop him off at a muggle hospital with no ID. A Catholic hospital so we'll know they won't pull the plug. [...] They'll keep him alive. If it's a really serious issue, we can compensate them later. [...] It's the same thing I was going to do to Runcorn... Unless you object, Kingsley. You have the final call if [you're] not uncomfortable. It's some risk to the muggles, but it shouldn't be much.
    • Hermione casts this spell again on Barty Crouch Jr in Chapter 12 of Annals, after learning that he outsmarted all of them by making his own Horcrux to put her family in danger.
  • Fingore: During the excursion for the Ring Horcrux, Hermione uses her stiletto knife to cut off Dumbledore's finger (with his consent) after he put on the Ring, in an attempt to stop the spread of the curse. However, it is unknown whether this was successful, since Draco Malfoy is able to kill him after he returns to Hogwarts from the excursion, with his spellcasting impaired by a mixture of the curse and the cut finger.
  • Finishing Each Other's Sentences: Other than the Weasley Twins, Harry and Ginny are able to do this by the Battle of Hogwarts, though it's justified in that they have become Mindlink Mates by that point.
  • Foregone Conclusion: Hermione's attempts to ensure that her map of the castle is architecturally correct fail because Hogwarts is always changing. She still tries to create a map without the correct measurements, though.
  • Foreshadowing:
    • Early in The Arithmancer, after Hermione has her Freak Out about Dementors, she worries about the hypothetical scenario of Luna being Kissed by one. Very late in Lady Archimedes, to Hermione's terror, that exact thing actually happens. And then she invents a ritual to undo it.
    • In Lady Archimedes, Hermione asks Anthony Goldstein to translate an ominous phrase into Hebrew; 'deplore' in the "plural imperative intensive form" — he says deplore doesn't translate and substitutes 'lament'. The answer, "Qanenu", is the invocation for the spell she calls The Deplorable Word. She also asks for a translation for "I cast you out, unclean spirit" — this one she uses in Biblical Greek, for two different spells — "S'ekballoume pneuma akatharon" for the de-Horcruxing ritual and "S'ekballo eis to skotos to exoteron, esy pneuma akatharon"note  for destruction of Dementors.
  • Fox-Chicken-Grain Puzzle: The Ravenclaw door gives puzzles in lieu of a password, of which this is one. Ginny suggests Cutting the Knot by casting Freezing Charms on the animals and conjuring a bigger boat, which the door deems an "acceptable alternative".
  • Gender-Blender Name: Invoked by Tonks, who names her baby "Sasha" because he is a Metamorphmagus like her, and can change their biological sex, but she herself dislikes her name due to it being very feminine and most likely doesn't want her son to endure the same.
  • Get a Room!: Dean heckles Harry and Ginny for their public display of affection, but since they're married and have their own accommodation, it gets him nowhere.
    Hermione: They've already got one Dean. I don't think it's going to stop them.
  • Get Out!: The Grangers have a downplayed version when Professor McGonagall tries to recruit Hermione for Hogwarts, at least until she proves magic does exist.
  • Gilligan Cut:
    • After Harry and Ron miss catching the train in second year, all their friends are discussing how Molly and Arthur probably used the Floo Network to get them to Hogsmeade and are enjoying butterbeer. Cut to Harry and Ron on the Knight Bus.
    • Arthur and Molly look over the photos of the Yule Ball, and Molly expresses concern about whether George's carelessness and lack of seriousness will corrupt Hermione. Cue scene change to Hermione working on a list of new hexes, starting with a Tooth Drilling Hex.
  • Godzilla Threshold:
    • As Snape is still alive during the Battle of Hogwarts, he uses the Killing Curse to instantly take down an attacking giant. This immediately makes him a target for several Killing Curses from Death Eaters.
    • Hermione crosses this during the final battle. She ultimately kills Bellatrix with her invention, The Deplorable Word, which she spent most of the book trying to keep secret.
  • Go Mad from the Isolation: Hermione name drops this trope verbatim when discussing Kreacher's mental health. It isn't normal for an elf to let their house decay into squalor, but he's been alone in the house for over a decade.
  • Good with Numbers: Hermione; that's the main premise. She can rapidly perform arithmetic on large numbers in her head, quickly picks up new fields of mathematical study, and is so devoted to maths that attempting to make her write a deliberately wrong equation caused her to break an Imperius Curse.
  • Grey Goo: Hermione worries that it might be possible to create a self-replicating device with the use of transfiguration and runecraft. It is — though fortunately it's hard to make it fully self-sustaining by accident.
    Hermione: Qanenu.note 
  • Groin Attack: Ginny is present when Peter Pettigrew is unmasked, and promptly kicks him between the legs for having previously (in his rat form) watched her get dressed. A few minutes later, Hermione learns that he watched her too, and kicks him again.
  • Happily Adopted: The son of Bertha Jorkins and Barty Crouch Jr, who is adopted by Septima Vector after the Battle of Hogwarts.
  • Happiness in Slavery: As per canon, even after being freed, Dobby still wants to work, and insists on low wages. When Hermione learns that the Hogwarts elves mistrust him and limit the jobs they allow him to do, she starts to wish there was a law preventing such treatment, and then realises that that would mean passing anti-discrimination laws to protect the free workers from the slaves.
    Her world was mad.
  • Head Desk: After having had three crazy years of Hogwarts, this is Hermione's reaction to Harry's name coming out of the Goblet of Fire.
  • Heart Is an Awesome Power:
    • Harry is not very impressed by the spells Hermione invents for him before the Second Task — until she makes him try them out. He quickly discovers that her strobing green laser is very jarring if it gets you in the eye, and when cursed to speak in iambic pentameter, he can't successfully cast a wide variety of spells, including those that might lift the curse. Cedric is later saved by learning to cast the green laser, because it travels at light-speed and throws off Barty Crouch's aim at the last moment.
      Hermione: I think I'll leave [the iambic pentameter curse] on and see how long it takes for people to notice.
      Harry: Hermio-n-n-NEE!
      Hermione: That's what you get for criticising my spells, Harry.
    • All her life, Hermione has had to deal with people asking, "What is maths good for?" The answer is that it lets her plumb previously unknown depths of magic, from molecular rearrangement that works like permanent Transfiguration without the usual five exceptions, to the invention of a plethora of new hexes and curses with remarkable effects like bypassing shields, to successfully using Ravenclaw's Diadem.
  • Hidden in Plain Sight: The Cup Horcrux is hidden in the ring of rune stones in the village Wellow, Somerset, located along a major Ley Line as opposed to a Gringotts vault.
  • Homeschooled Kids: In her fifth year, Hermione leaves Hogwarts after Christmas and gets tutorship from Slughorn.
  • Horrifying the Horror: Even a pack of Dementors is scared of Hermione after she kills one of them.
    Hermione: Boo!
  • Hypocritical Humor: When Sirius and Remus are cleaning out Grimmauld Place and doing battle with the pest species living there, Sirius starts with a fire spell, which Remus admonishes him about. Not much later, Remus gets startled enough to pull the same spell out himself.
    Sirius: Incendio!
    Remus: Padfoot, do you want to burn down the whole place?
    <Buzz! Buzz! Screech!>
    Remus: AHH! Incendio!
    Sirius: You were saying?
  • I Am Not Left-Handed: Hermione plays this 100% straight in her exhibition duel against Seamus Finnigan in fifth year, and revels in the opportunity to quote it in full.
  • I Call It "Vera": Nearly Headless Nick insists that a sword as impressive as Hermione's needs a name, so she engraves it with ᛊᚾᛁᚲᛖᚱᛊᚾᛇᚲ — "Snickersnack".
  • I Did What I Had to Do:
    • Hermione isn't happy with Dumbledore playing The Chessmaster with people's lives, and he doesn't enjoy it either, but he maintains that he is doing what he believes to be best.
    • Hermione herself is on the other end of this when her parents are upset by how she has become hardened to death and killing.
      Hermione: I'm not going to become a murderer, Dad. I'm not going to sink to his level. But I will defend myself and my friends. With deadly force, if necessary.
  • I Think You Broke Him: Stated by George when Hermione pays Dobby to help Winky get cleaned and sobered up, and insists on trying to help her pull herself together and get back on her feet. The other elves just stare, with their whole cultural background making the situation incomprehensible to them.
  • If You Ever Do Anything to Hurt Her...:
    • Subverted when Dan has an "obligatory father-daughter's boyfriend talk" with George; he says This Is the Part Where... he's supposed to threaten a root canal without anaesthesia, but admits that Hermione is far scarier than he is, and if George hurts her, she will take revenge.
    • Fred and George jokingly pull this on Harry when he attends the Yule Ball with Ginny; he's certainly intimidated, but he points out that George, who brought Hermione, should be more worried than he is.
  • Immunity Disability: Hermione, Lavender and Parvati have a very difficult time getting Hagrid presentable for the Yule Ball, because his hair is resistant to magic.
  • Implied Death Threat: Downplayed; Ginny isn't threatening actual death, but after chatting with Luna's bullies about how Luna's shoes have gone missing again, and how she expects her friends to be shown respect, she then mentions that the Twins are looking for testers for their prank products, and asks if they're interested.
    Ginny: Just something to think about. Toodles!
  • In Spite of a Nail: Because of The Stations of the Canon being at play, this trope is played straight such as in these cases:
    • The barrier at King's Cross is still sealed and Ron still gets a Howler from his mother.
    • Dumbledore still dies but it's Draco not Snape who does it.
    • The Ministry still falls to the Death Eaters.
  • Instant Birth: Just Add Labor!: Downplayed. Fleur was in labour for approximately three hours for her firstborn — not quite unrealistically short, but still much shorter than the average human, though it can possibly be justified that A Wizard Did It.
  • Intrepid Reporter: Rita Skeeter, as per canon, though she becomes a Nominal Hero in 'seventh year' to assist the Creevy brothers on reporting the human rights violations committed by the Muggle-Born Registration Commission, and seeks out Hermione to make a deal with her on this.
  • Intrinsic Vow: Hermione's devotion to maths means that she is able to throw off the Imperius Curse when told to write 2+2=5.
  • Just Friends: Harry and Hermione keep telling people this in the wake of an article by Rita Skeeter, but not many people believe them, especially since Hermione is a hugger and Harry relies on her help a lot throughout the Triwizard Tournament. In the end, though, they are indeed simply True Companions.

     L - Z 
  • Laughing Mad: Barty Crouch Jr laughs maniacally after being captured by Light forces in Chapter 12 of Annals, because he created a Horcrux to safeguard his life just in case that happens.
  • Ley Line: Britain's ley line network plays a part in the second and third fics, being how the Ministry of Magic maintains national spells. Most Wizarding homes are built on ley lines and their defensive wards tap into the energy from them. At one point, Hermione exploits continental drift in the ley lines to break into a Death Eater mansion.
  • Like Brother and Sister: Harry and Hermione, as per canon, to the point Hermione calls Rita Skeeter describing them as "sweethearts" in her first Triwizard article "ridiculous", but it's outright solidified when her Big Sister Instinct kicks in after Bellatrix tries to kill Harry for killing Voldemort:
    Hermione: (having reached her Rage Breaking Point) NOT MY BROTHER, YOU BITCH!
    Bellatrix: (incredulously) Brother?
  • Literal Metaphor: Cedric Diggory survives in this continuity, but as Hermione puts it, it cost "An Arm and a Leg, and no, that's not a figure of speech".
  • Loophole Abuse:
    • Quirrelmort gets through Professor Vector's trap by using a color-blind charm on her enchanted statues.
    • Underage wizards and witches can use wandless magic outside of school, as long they do not use it in front of Muggles that are not a Secret-Keeper. Hermione makes use of this just to get on even footing with pureblood children, who exploit the more egregious loophole that the Ministry can't tell who cast a spell (only what and where) and therefore ignores all spellcasting in magical homes.
    • Runes can be used to replace wands in potion making, allowing muggles to brew potions.
    • After refusing to be a hostage for the Second Task, Hermione and Dobby are not allowed to have any contact with the Champions. But Harry already has a communication coin from her.
    • One of Hermione's most common tricks against Dolores Umbridge throughout her fifth year is to take actions which there are no rules against, though the bureaucrat quickly adopts new rules to close the loopholes.
      • Umbridge bans teachers from giving students any information that isn't related to the subjects that they're paid to teach — so Hermione hands Professor Vector a coin and they continue discussing advanced Arithmancy as usual. When Umbridge finds out and bans teachers from teaching any classes outside the approved curriculum, Professor Vector starts paying Hermione a sickle per week to teach her "Advanced Topics in Mathematics", of which she is qualified to do so by Fifth Year. Umbridge ends up having to ban Hogwarts teachers from pursuing an active education while working as a professor at the school.
      • Later inverted, as Hermione discovers that there is a rule specifically stating that Hogwarts students are allowed to carry swords, one which is centuries old but still entirely viable.
  • Love Confession: George isn't in the best state of mind when he first tells Hermione that he loves her, but he's not joking about it. She needs some time to figure out how she's going to respond, but she does assure him that she's not going anywhere.
  • Love Potion: Reconstructed; Hermione is quite displeased to learn that the Twins plan to sell them given the ethical problems, but they explain that they're deliberately developing mild versions that won't be more than pranks, just making someone compose poetry, or blush, or at the most give a single kiss and then snap out of it. Of course, they do some experimenting on themselves first...
  • Mama Bear:
    • Harry doesn't fully grasp how bad it is to have to steal an egg from a nesting dragon, until Hermione offers him a hypothetical choice between fighting Bill Weasley or kidnapping Ginny from under Molly Weasley's nose. Upon considering that, his face goes pale and he concludes that he's going to die.
    • In Chapter 21 of Annals of Arithmancy, when someone attacks her and her children on Halloween, Hermione curses the area around him into a smoking ruin. She's surprised to find that he's still alive afterward — though he looks like a nightmare that she doesn't want the children to see.
      Later, she wasn't sure if he'd meant to cast at Emmy or if he was so drunk his aim was just that bad, but when she heard her daughter scream, that was when Hermione came down on the dark wizard like an avenging angel.
  • The Matchmaker: Ginny specifically recruits Hermione to help her get Harry's attention. Mostly Ginny just needs a nudge here and there to have the confidence to be herself around him, though.
  • Maternity Crisis: Fleur goes into labour in Chapter 67 of Lady Archimedes, just after her husband and several other family members escaped from Malfoy Manor during a mission gone wrong. She had to have a home birth in fear of Death Eaters guarding St. Mungo's hurting them.
  • Meaningful Name: Bill and Fleur's baby bears the given name 'Nadia' because it means "hope", quite fittingly for a child born into an era of war.
  • Medieval Stasis: Played for Drama and Played with. The Wizarding World seems perpetually stuck in the 17th/18th centuries, with an extremely authoritarian government that literally controls the press and exerts influence over education and academia, as well as seeming to lack any concept of civil liberties. On the other hand, the Wizarding World seems to be ahead of the muggle world regarding religious tolerance and sexuality (remembering of course that Harry Potter is set in The '90s).
  • Mindlink Mates: After doing a Hollywood Exorcism ritual to remove the Horcrux inside Harry, one of the consequences of the light magic is that it turns Harry and Ginny into light-oriented Horcruxes for each other. Deconstructed at first, it is very difficult to get used to and has a number of unpleasant side-effects. In the beginning they can't even look each other in the eyes without intense pain, and being unable to be physically separated is not as fun as it sounds. Things work out well in the end, though.
  • Misfit Mobilization Moment: After spending a year and half on the run from the Death Eater-controlled Ministry, the Battle of Hogwarts is this for Dumbledore's Army and the Order of the Phoenix.
  • Monumental Damage: Hogwarts Castle was so badly damaged by The Siege laid by Voldemort's forces, that in the aftermath Professor McGonagall declared the castle uninhabitable and the survivors had to create a tent camp by the carriage stand.
  • Mundane Solution:
    • Basilisk kills with a stare? Use sunglasses with lenses of a certain color designed to filter out the yellow of its eyes. Although "mundane" is selling what they do a little short — while the initial method of wearing sunglasses works, Hermione invents a spell on the fly to figure out the precise wavelength of light needed to block it out. And better? With them, she's able to look the Basilisk in the eye and only feel like she's got a migraine, rather than getting knocked out, paralyzed, or killed.
    • Instead of waiting a long time to get the Firebolt checked out by the teachers, they just send it back to the manufacturers and borrow a loaner until it can get checked.
    • Instead of flying a car to Hogwarts when Dobby seals the platform, Ron and Harry take the Knight Bus.
    • When trying to get at the Stone, Quirrell just steals the mirror the Stone is inside of, rather than sitting around and trying to puzzle it out in Hogwarts. He's still stopped, though, because the mirror was so big that it limited his escape paths.
    • Hermione deliberately builds a mundane solution into the D.A's contract as its obligatory Curse Escape Clause for the punishment for breaking it, banking that wizards wouldn't be likely to consider trying Muggle acne medicine. Though she acknowledges that Seamus's father, who is a Muggle, might suggest the idea.
    • This recurring belief lasts to the end of Lady ArchimedesVoldemort is able to use unsupported flight because his robes used flying carpet enchantments, rather than any obscure invented spell.
  • My Fist Forgives You: When Ron apologises for abandoning Harry during the first Triwizard Task, Harry and Hermione accept it, but Ginny smacks him in the back of the head.
    Ginny: Now we're good, you prat.
  • My Significance Sense Is Tingling: When a cut in Chapter 76 of The Arithmancer shows Ginny blowing up about Rita Skeeter getting her name wrong, Hermione (in a different country) turns to her friends and asks, "Did you hear something just now?" She concludes that she must have imagined it.
  • My Skull Runneth Over: Xenophilius Lovegood only lasts two seconds wearing Ravenclaw's Diadem before passing out. Hermione copes better and can actually use it, but needs to block out all unnecessary sensory input to reduce the load.
  • Nails on a Blackboard: One of Hermione's jinxes produces a cone of dissonant sounds that grates on the ear similarly to this. Its main advantage is that it takes very little strength to cast, making it an effective way for children to distract and delay an attacker while they escape or seek help.
  • Narrative Profanity Filter:
    • The fanfic makes liberal use of this, with many instances of characters cursing without descriptions of what they said. For example, in Lady Archimedes Chapter 61:
      Hermione responded [to Umbridge catching her in the Ministry with her Polyjuice worn off] with curses, and not all of the spell variety.
    • There's also a case where Harry's voice is muffled, but Hermione is pretty sure it consists of "words that even Sirius wouldn't let him say in front of him."
    • When Barty Crouch Jr wakes up in Ministry custody and is questioned, "his response was rather less than polite."
  • A Nazi by Any Other Name: The Death Eaters and later the Ministry when they take over, as per canon, but what solidifies this in the fic is that Hermione's first mental reaction to the Muggle-Born Registration Commission is to compare it to the Holocaust. According to Percy's information gathered in the Ministry before he had to quit and make a run for it, the Death Eater administration was going so far as to build a "Mudblood Relocation Camp" for the "final phase" of their plan (which happens to be canon to the films). After the war, Hermione speculates that the pureblood supremacy ideology of the Death Eaters might have been straight-up copied from the Nazis due to how similar they are.
  • Nerds Are Sexy: One of the reasons for Hermione and George's mutual attraction is that they can go toe to toe in terms of wits, intelligence, and problem-solving.
  • No Honor Among Thieves: Hermione internally observes this in Chapter 11 of Annals when a group of Dementors rats out and sacrifices one of their number to let the others get away.
  • Noodle Incident: A clan feud between Fleur Delacour and another part-Veela apparently came to a head when when their class brewed Love Potions, but the details aren't stated, except that it ended with both of them in detention shovelling out the stables, and exposed several unexpected relationships amongst the seventh years. Hermione knows more but wishes she didn't.
  • Not His Sled: The climax of each year is always different than it is in the books.
  • "Not Making This Up" Disclaimer: Hermione decides to prove the existence of a sixth Principal Exception to Gamp's Law of Elemental Transfiguration, namely, radioactive material, not for the prestige such an accomplishment would bring, but because she's terrified that someone might try transfiguring antimatter, and proving the impossibility of radioactive transfiguration is the first step in proving the same of antimatter. When she explains this to her parents in a letter home, she has to clarify that it wasn't a joke.
  • Not What It Looks Like: George wakes Hermione up on Christmas morning, but she's startled to see him in her room, and tumbles out of bed, knocking him over. Then her parents, having heard her yelp, hurry into the room — to see her sprawled across his legs.
    It wasn't hard to clear up the mix-up, though it did evoke quite a few red faces and some laughs from Fred, Harry, and Ginny. Traitors.
  • O.C. Stand-in: Being told from Hermione's perspective, we get to see the teachers that she, rather than Harry, interacts with, particularly Vector.
  • Off with His Head!:
    • Fenrir Greyback gets his head lopped off by Hermione with Snickersnack in the Death Eater attack on the University of Nottingham Hospital.
    • Nagini is beheaded like in canon, but dies to Harry wielding Snickersnack while retrieving/destroying the Cup Horcrux, as opposed to Neville wielding the Sword of Gryffindor in the Battle of Hogwarts.
  • Oh, Crap!:
    • In first year, Professor Vector pales in shock when Hermione tells her that Harry is going after the Stone by himself... and then pales further and bolts when she adds that he knows how to get past Fluffy, since that means he's going to encounter the Devil's Snare, which is much more dangerous. And both Vector and Harry are "chalk white with fear" when they see that Vector's trap, which she had thought arithmantically impossible for Hermione to bypass, much less an ordinary person, has somehow been defeated.
    • Professor Vector gets a fairly large one when Hermione reveals that her experiments could potentially create antimatter. Or at least, she gets one once Hermione explains what antimatter is.
    • Hermione is woken up by Harry's message telling her that the first Triwizard Task is dragons, and later insists that her roommates must have dreamed the words she said in response.
    • At first, Harry doesn't think that stealing an egg from a nesting dragon sounds all that bad; at least he doesn't have to fight it. Then Hermione points out how Molly Weasley would react to someone kidnapping Ginny, and Harry decides he's doomed.
    • Being very familiar with goblins, Bill quickly grasps the implications of Hermione's matter rearrangement spells, which is scary enough, but she isn't planning to make waves. And then she tells him that within a few decades, Muggles will be able to make diamonds using similar techniques.note 
      Bill: Remind me to take an extended holiday in Siberia when that happens.
  • One Drink Will Kill the Baby: During Annals of Arithmancy, the Weasleys are mentioned to have a tradition of drinking sparkling apple cider at Christmas, instead of anything alcoholic, because there's usually someone pregnant. In this case, Ginny is just a few weeks along with her third.
  • The One Thing I Don't Hate About You: Snape grudgingly admits that Hermione's potions publication was impressive and that he wouldn't be opposed to teaching her if she elected for independent study.
  • Only Known by Their Nickname: Sonya the House Elf's full given name is 'Sonnitt', but is only called that by her grandmother, Tilly, and the Hogwarts Professors.
  • Open Heart Dentistry: Ultimately subverted. Hermione, using the knowledge from her dentist parents' medical textbooks, tries to diagnose and perform surgery on Bill during the After-Action Healing Drama in Chapter 68 of Lady Archimedes. However, once she finds the medical conditions in question are more serious than she expected, she determines that he needs professional help or he'll die from his injuries. Harry ends up suggesting the family take him to a muggle hospital.
  • Our Ghosts Are Different:
    • Ghosts are Barred from the Afterlife and exist in an endless cycle, unable to grow mentally or gain new permanent memories outside of exceptional events.
    • There is an interesting contrast made with Portraits, which can learn and form new memories but have no capacity for creativity or true insight. Between a Portrait and a Ghost you would have a complete person.
  • Pædo Hunt: Downplayed. When the Granger read Hermione's Hogwarts letter they're creeped out that wizards can track the movements of children.
  • Parental Sexuality Squick: Upon finding out that Fleur is pregnant in Chapter 58 of Lady Archimedes due to forgetting to use the Contraceptive Charm, Molly remarks that Bill took after his father, and Arthur adds that she was referring to Ginny as she was conceived and born at the height of the war. The Weasley siblings respond in disgust to hearing about this.
  • Personality Powers: Hermione considers inventing a Tooth-Drilling Hex for Harry to use in the Triwizard Tournament, but eventually decides to save it for herself as the daughter of two dentists.
  • Perspective Flip: The series are told from Hermione's point of view (with a few scenes from other people's view). This flip is not just in terms of focus, but also shows narratively by, for instance, showing a deeper look into the actual classes at Hogwarts. Hermione's first transfiguration class is expanded from the one in the books, with Professor McGonagall giving a much larger speech about the nature of transfiguration.
  • Photographic Memory: Hermione gains this ability while wearing Ravenclaw's diadem, which she makes use of throughout her 'seventh year' to create various spells and rituals, among other things for the war effort.
  • Pop-Cultured Badass: Hermione loves making literary references and nerdy jokes, particularly in front of Wizards who have no idea what she's quoting. For example, she names her sword Snickersnack.
  • Powder Keg Crowd: Umbridge's attempt to stop Septima from rescuing Harry and Hermione from the Ministry of Magic marks the final straw for Dumbledore's Army, resulting in a riot that ends with Umbridge getting blasted across the room.
  • Practically Different Generations: Columba Malfoy is born in 1998, while her late brother Draco was born in mid-1980.
    It was hard to believe how different the two sisters [Narcissa and Andromeda] had turned out. On one side an aloof pureblood princess, and on the other side a woman who had married a muggle-born and who had a grandson the same age as Narcissa's daughter.
  • The Prankster:
    • Fred and George, as per canon. They even help Hermione fake a Death Eater attack and her parents' death, not just because George wanted to support Hermione, but also because it was a prank on the Death Eaters, and previously managed to pull a prank on Dumbledore with Hermione and Ron's help.
    • Other than that, the Weasley Twins slowly come to see Hermione as this due to the increasingly risky, highly illegal means she uses to deal with the dangerous occurrences at Hogwarts. This isn't necessarily the best description of her, as she's an Arithmancer by trade and by extension a Science Hero, but she does have a mischievous streak from time to time, and she first gains the Twins' respect by pranking them early in her first year.
  • Prematurely Grey-Haired: Bertha Jorkins is described to have "prematurely greying hair" by the time Snape rescued her at the start of the Battle of Hogwarts.
  • Professional Maiden Name: Lampshaded when George proposes to Hermione early in the Battle of Hogwarts.
    Hermione: I'm keeping my maiden name. It's too confusing building up a scholarly reputation when you suddenly have to change your name on all your papers.
  • Rage Breaking Point: It takes a lot to push Hermione over this line, but it can be done.
    • After nearly being Kissed by a horde of Dementors, Hermione just can't take Minister Fudge's pleased comment that they caught Sirius Black, and blows up at him for his actions in setting demons around a school.
    • Umbridge found that out the hard way when she threatens violence on Hermione and her boyfriend while she's infiltrating the Ministry with the Order in Chapter 61 of Lady Archimedes. Hermione snaps and curses her so badly that Umbridge is barely recognizable as human by the time she's pulled out of her rage.
  • Rape Is a Special Kind of Evil: Bertha Jorkins was held hostage and brutally raped by Barty Couch Jr for four years, and eventually became pregnant. She's rescued by Snape when the D.A. takes over Hogwarts from the Death Eaters.
  • Razor Floss: Once Hermione learns how to rearrange any source of carbon into nanotubes, she can fill an area with strands too thin to easily see, but strong enough and sharp enough to cut a man to ribbons. It requires additional magic to be held in enough tension to allow it to cut.
  • Real Witches Love Jesus: It seems that Hermione is a Christian in that she believes in God and immortal souls. This is why she is so shocked to find out that the Dementors might be capable of destroying souls, and has a minor existential crisis about it. Her faith is ultimately vindicated to an extent when she figures out how to kill a Dementor and the souls it has trapped are released.
  • Reasonable Authority Figure: Arithmancy Professor Septima Vector is this to Hermione.
  • Red Baron: Hermione has had a reputation for being "The Arithmancer" (with capital letters) since her fourth year, if not earlier. She goes by more 'titles' and aliases later on in the series, self-given or otherwise.
  • Red Herring: In Lady Archimedes, Hermione spends much of Chapter 77 searching for living wizards or magical creatures born in the British Isles on the same day as Tom Riddle, implying that she needs one for a ritual to kill Voldemort remotely. Only after the conclusion of an extended search does she explain that finding no such being is a good thing, as if they had existed, the ritual would have killed them as well.
  • Refuge in Audacity: After Umbridge passes an Educational Decree banning teachers from teaching outside of their schedule or curriculum, Hermione points out that classes that aren't accredited by the Ministry don't require a teaching certificate, allowing her to continue her studies with Professor Vector. But when Umbridge finds out, she bans that too.
  • Removed Achilles' Heel: In The Arithmancer, Hermione receives a letter of thanks from a curse-breaker who encountered a basilisk that had been deafened and was thus immune to the crowing of a rooster. Fortunately, Hermione's color-filtering goggles allowed the man to resist its deadly gaze and prevail.
  • La Résistance: As per canon, the Order of the Phoenix was one to Voldemort and the D.A. was one to Umbridge at Hogwarts, but it evolves into the formation of an active Resistance against the Death Eater-controlled Ministry by Chapter 55 of Lady Archimedes, with Hermione mentioning the WWII resistances by name.
    Molly: Join the Resistance? Since when is there 'the Resistance'?
    Hermione: Just mention the words, 'Mudblood Relocation Camp'. Trust me, Molly, there will be then. Every muggle-born will understand that.
  • Reverse Polarity: Lampshaded when Hermione visits CERN as part of her research into whether it's possible to transfigure antimatter in Chapter 10 of Annals; they really do use magnetic fields of opposite polarity to slow down charged particles for study.
  • Ritual Magic: Used extensively in Lady Archimedes. Hermione uses one to remove the Horcrux in Harry's scar, and in the process makes him and Ginny into Light-aligned Horcruxes. Another ritual is used to kill Voldemort in Chapter 79.
  • Roadside Surgery: After the raid on Malfoy Manor, Hermione attempts to diagnose and perform minor surgery on Bill Weasley in presumably the living room (or equivalent) of Prewett Manor, but this is ultimately subverted since the medical conditions in question become so severe that he had to be taken to a muggle hospital for treatment.
  • Rooftop Confrontation: Deconstructed when Hermione fights Bellatrix in the Great Hall rooftop after killing Voldemort for good, she slides down the rooftop, suffering tears in her robes and scraps. It's even given a Lampshade Hanging that rooftop fights are not as easy as in movies.
  • Rules Lawyer: In Lady Archimedes, Umbridge and Hermione have this back and forth. Hermione is smarter, but Umbridge has the upper hand because she has the backing of the Ministry and thus can change the rules at will.
  • Running Gag:
    • Hermione has a habit of hexing Voldemort and his Death Eaters in the face, which is naturally lampshaded every time it happened since Second Year.
      • Professor Quirrell gets paralysed from behind, where Voldemort's face is stuck on his head.
      • Diary!Riddle gets dazzled by a sunlight charm and his wand snapped.
      • Peter Pettigrew is hexed to pour beetles out of his mouth. And that one was left-handed.
      • In Fourth Year, while Hermione doesn't get to hex any Death Eaters in the face in person, Harry hits Voldemort with a Lumos Ardens (one of Hermione's invented spells) in the duel in the graveyard and says he did it for Hermione.
      • Years later, a puppet show for their children, retelling the war, includes a Hermione puppet that faces Volde-puppet and shouts "Hex in the face!" making him fall over.
    • The author notes for each chapter typically include a copyright disclaimer combined with a Shout-Out.
      Disclaimer test number 55: British? No. Female? No. Insanely wealthy? No. Probability of being JK Rowling: 0% within experimental uncertainty.
    • Professor Snape's robes always billow behind him, even when there doesn't seem to be any breeze and it doesn't fit his movement. Hermione suspects some form of magic. When Draco receives the Dark Mark, his robes start billowing too.
  • Run or Die: Confrontation with Voldemort is rightly treated as this by all the main characters. Whenever he takes the field, it rapidly becomes a Curb-Stomp Battle.
  • Science Hero: Hermione and the Twins really enjoy their detailed experiments into how toy wands work (and don't work), and their efforts result in Hermione being able to make backup wands that aren't detectable as underage magic.
  • Sensory Overload: The true power of Ravenclaw's Diadem is that it "opens [one's] mind to all of the information provided by [one's] senses, and all of [one's] memories, that [they] normally shut out", essentially bringing the conscious and subconscious together and removing the limitations of the mind. Unfortunately, without sufficient mental discipline, such knowledge is extremely overwhelming and can lead to sensory overload, or in cruder terms, drive one insane.
  • Shame If Something Happened: As Hermione protests the blood quill detention Umbridge prepared for her, the witch threatens her family because truancy is illegal in the Wizarding World — and the law makes no allowances for expulsion, so Umbridge could throw her out of Hogwarts and then effectively prosecute her (and her parents) for not being there.note 
  • Shout-Out: In Chapter 17 of Annals, the family puts on a puppet show for the children, where Harry at one point is feeling "cranky and pubescent today and I don't know why. Grrr! I'm gonna take it out on people I like."
  • The Slacker: While Ron is often accused of this, his ability to think quickly outside the box in contrast to Hermione ends up being crucial to the climax of their third year, in Chapter 57 of The Arithmancer.
    Ron: (smugly) I'm highly logical at doing things quick and dirty with a minimum amount of effort.
  • Slowly Slipping Into Evil: Hermione is very concerned that she herself is doing this under the stress of the war, and with good reason. Her brilliance and creativity go in some genuinely evil directions when she doesn't stop herself. Fortunately, she has her friends to keep her grounded.
  • Something Only They Would Say:
    • After Hermione suggests that Harry skip a class to prepare for a Triwizard Task, Ginny (jokingly) demands this as proof that she's not an imposter.
      Hermione: When second-order linear partial differential equations are written in four or more dimensions, those with more than one positive and more than one negative characteristic value of the coefficient matrix are classified as ultrahyperbolic.
      George: False alarm. It's her.
    • Harry later questions her when she arrives at the Dursleys' house in disguise.
      Hermione: A topological space is defined as a set of elements X and a collection of subsets of X, tau, such that the empty set and X are subsets of tau, any union of members of tau belongs to tau, and—
      Harry: Okay, okay! It's definitely you, but why do you look like that?
  • Soul Jar:
    • As per canon, Voldemort creates Horcruxes as safeguards for his immortality, but they are destroyed throughout the series.
    • In the late chapters of Lady Archimedes, Harry and Ginny become light-oriented Horcruxes (later named "Miracruxes") in the rituals used to remove Voldemort's soul fragment from Harry.
    • In Annals of Arithmancy, Barty Crouch Jr is revealed to have created his own Horcrux to safeguard his life from capture by Light forces.
  • Spared by the Adaptation: There's a fair list of them — Cedric, Sirius, Remus, Tonks, Fred, Astoria (using non-magical medicine and a fortifying elixir from Hufflepuff's Chalice/Cup to treat her blood curse), and possibly others.
  • Spark of the Rebellion: After George is flogged in the Great Hall and leaves the school, most of the school gives up any pretense of obeying the rules, hexing the Inquisitorial Squad and Filch at every opportunity, and even almost all the teachers turn a blind eye to everything that doesn't actively disrupt their classes (the only exception being Professor Snape).
  • Squee: When Lavender Brown sees who Viktor Krum has brought to the Yule Ball, she squeals "at a frequency that really shouldn't be anatomically possible."
  • The Stations of the Canon: Played with, but mostly played straight. All the events of the books occur with only superficial changes. Umbridge is much meaner than in canon, Dumbledore is killed by Draco a few months earlier, the Death Eaters take over the Ministry a few months earlier.
  • Sufficiently Analyzed Magic: It's not entirely there quite yet, but Hermione is on it.
  • Summon Bigger Fish: Hermione lays down the law to the students bullying Luna, by threatening to sic the Weasley Twins on them if the harassment continues. No one wants those two motivated and aimed at them.
  • Super Weapon: Hermione designs one as, essentially, a side project while figuring out how to remove a Horcrux from Harry. It involves runecraft, transmutation, and duplication charms. It couldn't destroy the world... unless you started it in the right place. She is appropriately horrified at what she created, and puts the most important parts of the work under Fidelius.
  • Super Window Jump: During her duel with Bellatrix, Hermione out of a window.
  • Take Our Word for It: Hermione says this to Bill Weasley as she's explaining to him the concept of continental drift, which he finds preposterous.
  • Take That!:
    • The last section of Chapter 68 of The Arithmancer is one to the Fandom-Specific Plot of magically arranged marriages.
      Parvati: (reading about magical contract law) Under the Marriage Reform of 1693, betrothal contracts are not valid unless signed by the actual parties to be married.
    • Hermione giving a briefing on the Horcrux Hunt to the inner circle of the D.A:
      Hermione: Just so you know, this won't be a job of traipsing around the country for months, camping out, and looking for the... items we need.
    • Harry and Ginny's second child is named William Kingsley.
      It was certainly better than, oh, Albus or something.
    • And another poke at a common fan plot of "Harry impresses the goblins and they would anything for him" in Annals, when Hermione is named a Journeywoman.
      Hermione: I didn't just crack some secret code to making the Goblin Nation my best friend, did I? As convenient as that would be, I don't think I could handle the absurdity.
      Flitwick: Certainly not, Miss Granger. The Goblin Nation has more dignity than that.
  • Taken Off Life Support: Discussed in Chapter 61 of Lady Archimedes, where Hermione explains what the term means to her co-members of the Order who were raised in the magical world. Since this trope is defied by Catholic hospitals, Hermione exploits this defiance to make a plan so as to deal with two Voldemort-aligned characters they captured without crossing the line of committing war crimes.
  • That Came Out Wrong: Hermione begs some Pepper-Up Potions from Madam Pomfrey to help her stay awake for 48 hours, and offers to let Madam Pomfrey tie her to the bed and force-feed her a sleeping draught afterward — then realises how that sounds.
  • There Are No Therapists: Hermione saw a counsellor during the summer after her traumatic experiences in her first year, which does help. However, she can't be entirely open, because her therapist isn't cleared to know about magic. After the war, she illegally tells her therapist the full story, knowing that she can get better results from full honesty.
  • This Is for Emphasis, Bitch!: Hermione to Umbridge when she has George Weasley attached to a whipping post at the end of fifth year.
  • Thou Shalt Not Kill: Defied. Unlike canon, our heroes have far fewer qualms about using lethal force while defending themselves if necessary, though they still frown on killing disarmed and captured enemies.
  • Tied-Together-Shoelace Trip: At the start of third year, Hermione tries to create a charm that would help her tie her shoelaces, as a first active attempt at spellcrafting. It doesn't turn out quite right and only manages to tie her shoelaces together. She later casts it on Draco Malfoy in Chapter 43, saving him from being attacked by Buckbeak.
  • Tim Taylor Technology: Wizards believe that Dementors are immune to heat and fire. Hermione takes the view that "if fire didn't destroy it, you haven't used a fire hot enough", and builds a ritual around a solar furnace.
  • Time Skip: Annals of Arithmancy is essentially a very long epilogue to the series, and as such, it starts off skipping over days, then weeks, then months, and eventually jumps over years at a time, just showing highlights from the important events.
  • Title Drop: In Chapter 63 of the first fic, Luna introduces Hermione to her father as "The Arithmancer". Hermione is bewildered to note that she's hearing capital letters.
  • Torches and Pitchforks: A mob of angry Slytherins run Harry out of Hogwarts in mid-sixth year, as Voldemort consolidates his control over the Ministry.
  • Trapped the Wrong Target: Played for Laughs when Hermione plans a prank on Fred and George involving runes set up to activate a waltzing jinx (of her own invention) on the next pair of twins to enter the Gryffindor common room. Unfortunately, she doesn't count on Padma Patil picking that day to come by for a visit...
  • Trauma Button:
    • After her experience in first year, Hermione doesn't cope with the introduction of four security trolls to guard Gryffindor Tower from Sirius Black.
    • Her NEWT exam takes a different turn when a narrow miss during a testing duel causes her to lose focus, and she starts reacting as if she's still in the war, changing from spells of binding and stunning to explosions, lightning, and pelting her opponent with shards of rock.
      Sirius ran out, shouting for her to stop, but she slipped his grasp. Why wasn't he fighting? She dodged both him and the Death Eater as she kept it up.
  • True Love's Kiss: Downplayed. One of the steps of the de-Horcruxing ritual Hermione devised to remove the Horcrux from Harry was a kiss of true love.
  • Understatement: Hermione learns from Madam Marchbanks that one of the other two geniuses she's tested was Tom Riddle, but Madam Marchbanks doesn't realise who he became.
    Hermione: I met him once or twice...but we didn't get along.
  • The Unmasqued World: Annals of Arithmancy ends with Hermione proving that surveillance and the Internet will eventually make the Statute of Secrecy untenable, and the best option is a controlled reveal. The final chapter reviews the speech that she's about to give on as many media platforms as possible.
  • Unusual Pop Culture Name: It doesn't actually happen, but George suggests to Ron in Chapter 18 of Annals that he should name his firstborn Inigo Montoya Weasley if it's a boy.
    Juanita [Ron's wife] had not been amused. Ron was even less amused when he learnt the character's backstory. That may have been the most impressive prank the family had ever seen him pull.
  • The Unpronounceable: Parodied with the infamous Welsh town which Harry, Hermione, George and Ginny visit in Chapter 70 of Lady Archimedes while on the run from the Death Eater-controlled Ministry.
  • Values Dissonance: In-universe.
    • The Goblet of Fire, being a medieval magical artifact, runs on this, as it allows people to be entered into the Triwizard Tournament by any authority figure over them. Professor McGonagall cites this to rebuke the concerns that other magical contracts also be able to force people to do things against their will, like the Goblet's contract did with Harry regarding the Triwizard Tournament.
    • In Chapter 64 of Lady Archimedes, throughout Hermione's investigation of her Soul-Detection Charm, she uses a Hindi-based incantation to refer to a Judeo-Christian concept, which results in several philosophical debates over the definition of a "soul" as her spell detects.
  • Voice of the Resistance: In Lady Archimedes, there are two — Radio Free Britain (of which "Potterwatch" is a segment) on the Wizarding Wireless and the Liberation newsletter, the latter succeeding from The Quibbler after a Death Eater attack on the Lovegood residence.
  • Walpurgisnacht: The Battle of Hogwarts occurs during this.
  • War Arc: Lady Archimedes spans Fifth to Seventh Year, i.e. the Second Wizarding War.
  • War Is Hell: Primarily throughout Lady Archimedes and Annals of Arithmancy, the cost of the war is fairly heavily emphasized, including a note on how the Battle of Hogwarts, with 43 casualties on the Light side alone, was devastating on the already-small magical population on the British Isles, and some of the younger students didn't even want to return to Hogwarts after their older siblings perished in battle there.
  • Weak, but Skilled: Quite a bit of Hermione's spell research focuses on making spells efficient, so that teenagers can fight dragons and Death Eaters. She uses the environment (e.g. extracting explosive magnesium powder from the soil), targets weaknesses (e.g. standard magical shields allow light and sound to pass through), and scours her parents' medical textbooks to design lethal and nonlethal takedowns with minimal energy requirements (it doesn't actually take much properly applied force to stop a heart). Even first- and second-year students can use her spells to effectively defend themselves.
  • What Have I Done: After their investigations into toy wands result in a homemade model that works approximately as well as store-bought ones, Hermione then realises that she has just given the Twins a way to use underage magic at home.
  • "Where Are They Now?" Epilogue: The Annals of Arithmancy which, while mostly focusing on Hermione, are this.
  • White Magic: Used especially in the Lady Archimedes. The Horcruxes in Harry and Ginny created accidentally by Hermione and the ritual to kill a Dementor in order to restore Luna's soul are good examples of this. However, the text itself refers to the trope by Light Magic.
  • Why Don't You Just Shoot Him?: Subverted; they do try to just shoot Voldemort with a transfigured sniper rifle during the Battle of Hogwarts, but since he's familiar with muggle weapons, he has appropriate protection.
  • A Wizard Did It: Played for Drama regarding Hogwarts' Alien Geometries, where this confuses Hermione greatly during her map-making project in her earliest years.
  • Wizard Duel: Several throughout the series, and Hermione spends a lot of time refining her dueling technique and devising strategy. The final battle in particular devolves into one, while Hermione is laboring under a curse that forces her to fight alone. It is appropriately epic and collapses the Astronomy Tower. It is not with Voldemort, who was killed with ritual magic, but with a grief-maddened Bellatrix.
  • You Are Better Than You Think You Are:
    • Hermione points out that while Ron sees himself and his family as normal, not one member of his family doesn't excel at what they do.
    • She has to verbally beat both of her friends into submission to take more advanced classes than the "easy O" classes of Divination and Care of Magical Creatures, pointing out that the two are actually really good at what they do — Harry's mind is fine enough for Arithmancy (with the added benefit of him having muggle schooling, which is better at maths than the wizarding counterpart), and Ron is better at Runes than Hermione is (partly because he loves languages more than she does).
  • You Do Not Want To Know: Professor Vector warns Hermione that she'd be better off not knowing all about what is under a Dementor's hood, and particularly the Kiss. Hermione is incredulous at the idea that it's better not to know something. Professor Vector is right; learning that souls are real but not indestructible sends Hermione into a Heroic BSoD, followed by puking up her lunch, and she's not properly functional for days afterward as she tries to come to grips with the existential horror of it.
    Professor Vector: Miss Granger, as a scholar I very rarely say this, but you should not ask questions you do not want to know the answers to.
  • You Have GOT to Be Kidding Me!: Bill first insists that Hermione must be joking about Muggles being able to synthesise flawless diamonds within the next few decades, then once he realises that she's serious, he starts talking about taking an extended vacation to Siberia.
  • You Have Researched Breathing:
    • Lampshaded by Hermione when her research and experimentation into magical extraction and purification of elements, making use of a suite of existing spells and new ones she's invented, plus modern technology like a Bunsen burner, results in a usable bronze knife.note 
      Hermione: Great. I now possess the technology of 2500 BC.
    • She later decides to finish studying for her NEWTs after receiving both a Mastery and Doctorate of Arithmancy.
  • You Wouldn't Like Me When I'm Angry!: Several characters decide that they do not want Hermione to ever get mad at them, such as Harry, after trying out the flashbang spell that Hermione invented in twenty-four hours to fight dragons for the first Triwizard task.
  • You're Drinking Breast Milk: One of the steps in the de-Horcruxing ritual involves consuming "the Milk of Human Kindness", as an inverse of a step in the original Horcrux-creating ritual.
  • Zerg Rush: The triskelia of the Deplorable Word are just a millimetre across, their individual attacks are like pinpricks, but since they consume all available material to self-replicate, there are enough of them to gradually flay Bellatrix Lestrange alive, starting with her hands and then her tongue to inhibit her spellcasting, then her Achilles tendons to stop her from running, and eventually eating all her organs.

Give me a place to stand, and I will move the wiki.