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Fanfic / Dexter's Lab: Equestria

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Dexter's Lab: Equestria is a Crossover Fanfic between Dexter's Laboratory and My Little Pony Friendship Is Magic. It was written by Renegade Alias and can be found here.

Dexter is a boy super-genius with a disdain for anything girlish and no desire for friendship. After an mishap in his lab, he get stuck in Equestria. How will he cope with the over-friendly ponies, and the girlish everything?

A side story called Nightmare Trip details Dexter traveling back in time and witnessing the rise of Nightmare Moon.



  • Achievements in Ignorance:
    • Despite not knowing anything about magic — or even believing it exists at the time — Dexter manages to complete a famously unsolved mathemagical equation called "Clover's Conundrum".
    • Even as he completely disbelieves that Celestia and Luna are solar body-manipulating immortals, Dexter inadvertently proves by scientific reasoning that Luna must be the magically/physically stronger of the sisters, since she controls both the moon and the stars. Much to Luna's pleasure, implying that this is actually true.
  • All Just a Dream: Dexter, when he first arrives in Equestria, believes he is just dreaming or simply hallucinating. He eventually jerry-rigs a diagnostic machine just to prove he is hallucinating. It calls him dense.
    • After finding out that Equestria really is a geocentric system, Dexter suffers a mild psychotic break and temporarily starts insisting he's in a dream again.
  • Alternative Character Interpretation: In-Universe. Ponies who hear about her think Dee Dee is a psychopath. Dexter is adamant that she's not evil, just an idiot.
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  • Amusing Injuries: Dexter's torment at the hands of Dee Dee come across as funny to the observer. To the ponies, who hear about it from Dexter, not so much.
  • Arson, Murder, and Jaywalking: Dexter comments in chapter 9 that Dee Dee's list of offenses against him include beating him up, setting him on fire, exposing him to toxic fumes, throwing him off of high places, destroying his possessions, zapping him with electricity, stealing his lunch money, intentionally exposing him to germs, detonating a bomb in his bedroom whilst he was sleeping, and causing him to get an A- mark in school.
  • Badass Bookworm: As in his home series, Dexter proves that being an eight-year-old antisocial genius doesn't keep him from being one grade-A flank-kicker. He fights Changeling infiltrators, steals his technology back from under Luna's nose, and prevents a major temporal disruption by first talking Discord into fighting Nightmare Moon, and then arranging for Celestia to blast both Discord and Nightmare Moon at the same time.
  • Chekhov's Gun:
    • The diagnostic machine is able to identify ponies as being Changelings. The machine makes Dexter a target of the Changelings, and a subject of interest among the Princesses.
    • Dexter's laser pen, which he used to torment Diamond Tiara, helps him defeat a changeling that was disguised as Cheerilee.
  • Child Prodigy: Dexter. Even without revealing the full extent of his scientific abilities, his interest in science rivals that of Twilight, and is able to solve an Equestrian concept called "Clover's Conundrum" that has baffled even the greatest scientific and mathmatical minds in Equestria for centuries.
  • Cool and Unusual Punishment:
    • Rarity inflicts this upon Dexter for playing a role in blowing up Carousel Boutique: Make him wear one of the hats he destroyed, and then introducing him to Pinkie Pie.
    • After he inadvertently uses the word "procreation" in front of the Cutie Mark Crusaders, Rarity then instructs them to catch him and play dress-up by phrasing it in terms of getting their Cutie Marks.
  • Creepy Child:
    • Holo!Dexter invokes this, deliberately channelling the personality of a certain other Dexter to help intimidate a captive changeling.
    • Dexter does this to frighten Twilight Sparkle when she tries to make him solve Clover's Conundrum again.
  • Domestic Abuse: Applejack, at the least, has suspicions that this is what Dexter's homelife involves, since his parents show no signs of coming to get himnote  and, to her blatant horror, her status as the Element of Honesty means she knows every word Dexter says about what his sister has done to him is true. In chapter 10, she confronts Dexter about what his sister has done to him, and notes that child support services would probably not let him go home if they believed his sister would go back to abusing him that way.
    • It's unclear so far if this perception of Dexter's family as abusers, admittedly out of ignorance and obliviousness rather than directed malice, has any impact in the Wham Line Dexter gets in the finale of Nightmare Trip.
  • Dramatic Irony: When Twilight confronts Dexter about the solution to Clover's conundrum, he calls her out on how Earth pony scientists have their work neglected because they weren't unicorns, Twilight responds that creatures who lack magic can't do much to study magic. Let's remember to whom she's saying this to, an incognito representative of another species without magic.
  • Double Standard: Abuse, Female on Male: While Dexter doesn't consider it abuse, when the Mane Six hear of Dee Dee's various physical abuses they're horrified.
  • Expy: In-Universe, Dexter considers Pinkie Pie, with her extroverted and excitable behavior, her pink color, and blue eyes, to be one for Dee Dee. This fills him with enormous amounts of grief, and he actually calls her Dee Dee on instinct.
  • Fantastic Racism: Tribalism is apparently a very real and serious problem in Equestria. In chapter 9, Pinkie Pie mentions that unicorns have pretty much dominated all scientific fields for decades and so nobody really believes/trusts in scientific proofs established by non-unicorns. This is why she knows pi to over 50000 digits, as a result of studying old earth pony scholars, when Twilight mentions that unicorns have only been able to calculate the first 400 digits of pi. Dexter finds this fact to be absurd.
  • Flat-Earth Atheist: Dexter has the uncomfortable position of being a rationalistic skeptic in a world that genuinely does run on magical principles. Much to his discomfort as he keeps finding out that his "rational" assumptions are wrong and, yes, the ponies are telling the truth. His sheer level of skepticism arguably pushes him close to Hollywood Atheist, but he does make painstaking rational arguments. For example, even after being forcibly confronted with the fact that Equestria is a geocentricnote  world, he refuses to believe that the Princesses are responsible... because how could life have ever evolved over billions of years if two individuals have to physically control the sun and moon? He's still wrong in his assumptions, but his reasons for being skeptical are rational. He's just insisting on applying real-world scientific fact to a world that runs on magic.
    • To put this in perspective, Dexter tells Luna to her face that he doesn't believe she manipulates the sun and moon, or even that she ever became Nightmare Moon.
  • Funetik Aksent: Averted; Dexter's trademark German-ish accent isn't spelled out in his dialogue at all.
    • Luna thinks to herself in chapter 11 that Dexter has " of the weirdest accents she had ever heard”.
  • Gadgeteer Genius: Dexter, as in canon. In a technologically backward society like Equestria, he is a able to build a complex diagnostic machine decades ahead of anything Equestria's ever built, a laser pen, and using salvaged parts from a junkyard, is able to construct a lab, complete with an AI computer. But like canon, he hides it from those around him.
  • Genius Ditz: Pinkie Pie. She is able to calculate the last 9 of 50001 digits of pi, can calculate the amount of time between when she felt her Pinkie Sense and when she met Dexter, and can interpret Dexter's complex language to realize he insulted her.
  • Good Cop/Bad Cop:
    • Dexter ends up doing this with his hologrammatic double after he finds Quadraplex's behavior to be too intense to handle.
    • Dexter invokes and discusses this with Luna as part of his attempts to disprove the "propaganda" of the Alicorn Sisters controlling the orbits of the sun and moon.
  • G-Rated Drug: After Dexter has a breakdown over finding out Equestria genuinely is a geocentric system, Quadriplex tries to calm him down by giving him a dose of a type two neuroleptic compound created from a plant Dexter discovered bordering the Everfree. The result is an intensely euphoric sensation... or, in layman's terms, Dexter is temporarily stoned out of his mind.
  • Heads I Win, Tails You Lose: Luna and Dexter try to out-smart the other with their knowledge of the cosmos; if Dexter loses, then he has to go with Luna and Pipsqueak to celebrate Nightmare Night. Dexter, still thinking Luna was passing propaganda as fact, nonetheless managed to make the princess stumble. His reward? He gets to celebrate Nightmare Night with Luna and Pipsqueak.
  • Heroic BSoD: Pinkie gets one when Dexter insults her. It lasts like... five seconds, before her hopes for Dexter being her friend are rekindled.
    • Dexter later gets one when he fails to see the Milky Way Galaxy, when his distance from home and his family sinks in, as he would have to be at the very least in a different galaxy.
  • Jerkass: Dexter is as antisocial and egotistical as per canon, but it really stands out among the residents of Ponyville. Highlights include insulting Equestrian history, making (unintended) derogatory remarks about the various tribes, and calling Pinkie Pie stupid.
    • Jerk with a Heart of Gold: Underneath his angry exterior, he has quite a few redeeming features. He does deeply miss his family, even Dee Dee, and breaks down crying when he realizes they are literally a galaxy away. He also risks exposing his scientific genius to give a letter to the Royal Guard so they can rescue Cheerilee after she is captured by the Changelings. He is adamant about stopping his computer from torturing a captive changeling, and after her interrogation is finished, he's so disturbed by her intensity he orders her to perform a diagnostic exam on her ethical programming. It's implied he wants to keep the ponies of Equestria from hurting themselves with his technology because he'd feel guilty if that happened. In chapter 9, he chews his computer out for not taking the potential presence of infants into account when he has to sedate a building full of ponies. When he inadvertently convinces some ponies that his sister is a psychopath, he spends an hour trying to convince them that isn't the case and she's not malicious at all, merely a moron.
  • Insufferable Genius/Know-Nothing Know-It-All: Dexter comes across as this with his dismissal of things that Equestria regards as common knowledge. Cheerilee does recognize his brilliance at math and science, but by academic standards recognize him as fairly average, considering his lack of basic magical and historical expertise. This annoys Dexter to no end.
  • Laser-Guided Karma: Literally. When Diamond Tiara mocks Dexter, he shoots her tiara with his laser pen and sets her crown on fire. Ironically, this was an accident rather than Disproportionate Retribution; Dexter just wanted to ruin the finish, he didn't realise that the crown was actually a fake.
    • Dexter too undergoes this when he acts too much like a jerk.
  • Living Lie Detector: Applejack, being an Element of Harmony, is able to detect lies, which makes it difficult for Dexter to hide his scientific brilliance and forcing him to speak in a way that makes him technically correct. Even more so are Changelings, based off their ability to sense emotional responses. The changeling posing as Cheerilee not only knows Dexter is lying about the machine, but is able to determine based of his biological response to her presence, that he not a pony.
  • Magic Versus Science: Zigzagged. Dexter initially doesn't believe in magic and is skeptical of it. Although he comes to accept after interacting with ponies that magic is real, he still remains skeptical about many of the claims that the ponies casually make, such as the abilities of the princesses or the pegasus ability to manually manipulate the weather. Dexter also hates the philosophy of "it's magic, it just works that way". Despite that, he finds the subject interesting and immediately starts trying to study it himself. The two forces are clearly separate, but can interact in some ways — Dexter is able to teleport his ion blaster out from under spells that should have prevented any teleporting spell from working and build magic dampening systems.
  • Mama Bear: Quadraplex, the AI Dexter built, had no qualms about torturing the changeling that tried to hurt her creator, to Dexter's horror. When Dexter tries to detonate his ion blaster to prevent Princess Luna tracking him down, she captures Dexter himself to try and force him to agree to be more careful about himself. She later restrains him and injects him with an anti-psychotic drug after he goes into a fit when he realizes that Equestria's sun doesn't work like Earth's.
    • Luna herself is furious when she learns Cheerilee was kidnapped by a Changeling, meaning they are targeting foals.
  • Mistaken for Racist: Dexter is accused of being prejudiced when he calls unicorn language and magic stupid. He merely disbelieves the latter, and finds the former to be dumb. Soon after, he gets a dressing down from Twilight and Applejack over more inadvertently tribalist dialogue.
  • My Greatest Failure: Besides the whole Nightmare Moon thing, Luna is deeply ashamed of the fact she didn't notice the Changeling Invasion during "A Canterlot Wedding" and thus didn't do anything to help.
  • Mythology Gag:
    • Before rooming with the Apple family, Dexter suspiciously asks about their opinions on science, indirectly referencing an episode where he was sent to an extremely primitive farming community and almost wound up being burnt at the stake for creating a potato-powered lightbulb.
    • In fact, Dexter references a lot of his experiences in order to explain his actions.
  • Not Now, Kiddo:
    • Dexter routinely receives this treatment, as it's obvious to the natives that this "silly little foal" has absolutely no idea what he's talking about, due to his ignorance of the way their world works and stubborn refusal to accept what he's simply told about.
    • Spike is reduced to yelling at the top of his voice to keep the ponies from shushing him and keeping him from telling them what he saw during the fight in the bakery.
  • Pet the Dog: In chapter 9, Dexter realises that Pinkie Pie does not share Dee Dee's sheer aggravating stupidity and makes a sincere effort at apologising to her for the way he's treated her.
  • Physical God: Implied in regards to the alicorns. Most notably, Princess Luna is capable of actually perceiving and attempting to interact with Dexter when he is moving at 60 times normal speed (although he's still fast enough she can't make out his precise features or quite catch him) and effortlessly shrugs off warding spells she warned would leave most ordinary people in a coma for a month at best.
  • Poor Communication Kills: Lampshaded. Dexter at one point mentions that the biggest reason he's evaded questioning and eventual discovery is because Luna, Twilight and Applejack aren't communicating with each other more, and thus allowing them to piece together vital information.
  • Pragmatic Villainy: The changelings reveal to Dexter that they haven't gone after the Elements of Harmony, and ideally never will, because they would lose their only defense against dangers like Sombra and Discord if they were taken out of the way.
  • Punctuated! For! Emphasis!: In Chaper 8 Colt of Genius Vs Changeling, Dexter is instructing his computer to interrogate the changeling.
    Dexter: You. Are. Not. To. Hurt. The. Changeling. Understood?”
  • Refusal of the Call: At the end of Nightmare Trip, upon being confronted by the ponysonifications of the Elements of Harmony, and hearing their intent to "mold him" into someone suitable to bear all of them on his own, Dexter gives them his strongest rejection. The Elements take this in stride, asserting that he will eventually embrace friendship of his own accord, and that will make him "fair game" for them. Dexter is skeptical of this, to put it mildly.
  • Sanity Slippage:
    • Twilight, after Dexter's solved Clover's Conundrum. She spends nine hours examining it, sending letters to and from important professors, and teleporting about the library. She calms down after Rarity dumps buckets of water on her head... only to see Rarity accidentally erased the blackboard in the process. Then she remembers that Dexter was the one who wrote it, and waits for him anxiously at Pinkie's surprise party. And the morning after the changeling attack, Twilight slips back into her manic phase when asking about the Conundrum.
    • Dexter, when observes the sun revolves around Equestria. He starts banging his head against a monitor, until Quadraplex restrains him.
  • Skewed Priorities: After reciting the litany of offenses that Dee Dee has made against him, Dexter initially believes that their horror comes from her causing him to get a less than ultra-perfect grade. In his defense, his next assumption is that it's the "blew him up with a bomb" thing... whereupon he assures them that the bomb had no shrapnel, so he was just slammed into a wall instead of being perforated or blown to bits.
  • Spanner in the Works: Dexter builds a diagnostic machine that detects a changeling in Ponyville's hospital, and he ends up uncovering a Changeling plot to infiltrate all levels of Equestrian society.
  • Sociopathic Hero: Dexter is frequently called a "borderline sociopath" in the narration. Knowing Dexter, he likely diagnosed himself as such at one point.
  • Stealing the Credit: After reading the proof to Clover's Conundrum Dexter left in her blackboard, Twilight excitedly starts sending the answer to as many institutions as she can and receives many excited responses awaiting for the method needed to reach said answer. When confronting Dexter about said method, Dexter points out all those institutions thought Twilight had been the one to solve the Conundrum, and accuses her of this trope, knowing full well that had Twilight mentioned Dexter, an earth pony, had been the one to solve it, there would be far less attention, as earth pony mathematicians are rarely taken seriously. He promptly pokes holes in her speciesist logic and leaves her rattled, as while she has the proof, she can't explain the necessary math. Later on, Twilight is forced to choose between answering, thus completing the trope (cementing everything Dexter has accused her of) or crediting Dexter and ensuring the knowledge is entirely ignored.
  • Stuff Blowing Up: Dexter decides to perform a chemistry experiment with the CMC, and ends up destroying Carousel Boutique by accident. Rarity is not amused. And Twilight will not let Dexter anywhere near her lab.
  • Stupidest Thing I've Ever Heard: Dexter's response to the whole Canterlot Wedding story, actually to a lot of things until a changeling itself targets him over his diagnostic machine.
  • The Voiceless:
    • Twilight renders Rarity this in her zeal to analyze Dexter's answer to Clover's Conundrum after Rarity tried to calm her down. Rarity splashes cold water all over the place.
    • In the side story Nightmare Trip: Dexter meets the physical personification (ponyfication?) of the elements of harmony in a dream and they take the forms of the mane 6 as avatars because that's how he knows them. Up to this point he has yet to interact with Fluttershy other than seeing her in passing, when the Element of Kindness is speaking to him he can't hear her because he hasn't heard the real Fluttershy's voice yet. The other elements fill him in on what she said.
  • The World Is Not Ready: One of the reasons Dexter hides his genius is because he feels the ponies are too backward to use it properly.
  • Time Travel: Dexter doesn't believe the claims that Luna and Celestia are immortal, and doesn't believe in Nightmare Moon. His solution? Build (a new) time machine to witness and record the perfectly-normal day and prove the propaganda false. Predictably, it all goes to hell in a handbasket.
  • Too Dumb to Live:
    • Dexter's opinion of Dee Dee, and he assures his pony audience that Dee Dee's affronts to him are caused by sheer idiocy, rather than any actual deliberate malice.
    • Spike saw the ion cannon in action, yet the first thing he does after picking it up is pull the trigger. Fortunately it wasn't aimed at anyone so there were no casualties.
  • Verbal Backspace: Spike does one quick-smart after realising he's just insulted Rarity's weight.
  • Wham Line: In the finale of Nightmare Trip, the Elements tell Dexter that they could send him back to Earth... but they won't, because Kindness and Generosity both believe that this would only cause him more suffering.
  • Would Hurt a Child:
    • The changeling posing as Cheerilee was willing to hurt Dexter to find out what he knew about the diagnostic machine. She later claims she was only trying to intimidate and wouldn't have actually injured the colt, it's not clear if she's saying that to gain sympathy or if she's being honest.
    • In the side story Nightmare Trip: Nightmare Moon kickes Dexter through a stone pillar to prevent him from delivering the elements to Celestia. Without his high tech armour he surely would have died, even with it he was badly injured. Luna spent her entire banishment believing she killed a foal, it's not clear if Celestia filled her in on Dexter's survival upon her return to Equestria in the first MLP:FIM episode.
  • You Got Guts: Luna actually likes Dexter's contrary nature... but at the same time warns him not to underestimate her.

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