Follow TV Tropes


Recap / Doctor Who S36 E1 "The Pilot"

Go To

Doctor Who recap index
Twelfth Doctor Era
Series 10: CS | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | CS
<<< Series 9 | Series 11 >>>

The Pilot
Click here to see the Radio Times magazine poster for this episode:
Written by Steven Moffat
Directed by Lawrence Gough
Air date: 15 April 2017

"Time is a structure relative to ourselves. Time is the space made by our lives where we stand together, forever. Time And Relative Dimension In Space. It means life."
The Doctor

The One With… the starry-eyed lass.

The Series 10 premiere of Doctor Who is also the proper debut story for new companion Bill Potts.

The Doctor has settled down as a university professor with Nardole as his ever-bickering assistant, watching over a mysterious vault (no, he's not in it this time). Bill Potts is a bright twentysomething lass who has a job serving chips on campus. Circumstances have led her to sitting in on his lectures, fascinated by his thoughts on time and space, and he, in turn, shows curiosity towards her peculiar behaviour — how she isn't upset by what she doesn't understand, but fascinated and excited about it. He decides to become her tutor, free of charge provided she lives up to his strict academic standards. But even so, the newly-minted student has no idea of just how curious he really is.

Bill finds herself gradually sucked into the Doctor's strange life, and the Doctor finds it hard to resist stepping back into his days of TARDIS travels. Some months after their teacher-student relationship begins, trouble brews when Bill meets a troubled girl — Heather, a woman with a distinctive star-shaped flaw in her left eye — while seeking affection from a special someone. It's Bill and Heather who end up growing closer together, but the latter becomes a little too drawn to an alien puddle and gets assimilated for her trouble, transformed into an aqueous aberration stalking Bill at every turn. The Doctor must intervene before Bill becomes a victim, even if that means giving her the skinny on his secretive lifestyle.

If you were looking for the actual pilot episode of Doctor Who, you'll find it here.


  • Adaptive Ability: The Doctor theorises that the Puddle is a left-behind piece of a spacecraft made of liquid that can adapt to any needed part during travel.
  • Aliens Speaking English
    Bill: TARDIS. If you're from another planet, why would you name your box in English? Those initials wouldn't work in any other language!
    The Doctor: People don't generally bring that up.
  • Always Chaotic Evil: Discussed; the Doctor tells Bill that while nearly everything in the universe is dangerous, very little of it is evil. Mostly, things are just hungry for something or other, and it's very easy to mistake hunger for evil when you're on the wrong side of the fork.
    The Doctor: Or did you think your bacon sandwich loved you back?
  • Answering Echo: Nearly everything the Puddle says (both as Heather and then as a Dalek). The one exception is her last line; when Bill says, "Goodbye, Heather," she responds, "Goodbye, Bill."
  • Arc Word: Promise. It is a promise Heather makes to Bill that leads to the latter being imperiled, and the Doctor has "promises to keep" that are yet to be revealed — ones that almost lead him to mind-wiping Bill.
  • Armed with Canon: This is the second time, after "Hell Bent", that Ten's wiping of Donna's mind has been referenced as a very bad thing, and something that the Doctor should never have done or should ever do again. As tends to be the case with this trope, it's become a Lost Aesop by the next showrunner and "Spyfall".
  • Ask a Stupid Question...: Bill wants to know how you can make a room Bigger on the Inside.
    Nardole: Well, first you have to imagine a very big box fitting inside a very small box.
    Bill: Okay.
    Nardole: Then you have to make one. It's the second part people normally get stuck on.
  • Assurance Backfire: The Doctor takes the TARDIS to the Vault to see if the Puddle is after what's in there. When they get there they find the Puddle entering.
    Nardole: What if it attacks us?
    The Doctor: Well, that's the good news. It means it's not interested in what's inside the vault. It just wants to kill us.
  • BBC Quarry: At least this one has CGI alien plants and exotic rock formations.
  • Big Bad: The sentient Puddle. It doesn't seem to be malevolent, but its dogged pursuit of Bill is what drives the plot.
  • Bigger on the Inside: Bill notices this about the TARDIS, although the Doctor and Nardole do comment on the fact that it takes her a while to realise.
  • Birds of a Feather: The reasons for the Doctor's interest in Bill are obvious — she's curious by nature (turning up at his lectures when she doesn't have to), she tends to ramble on without addressing the subject at hand (the chips story), she's intelligent but is interested in everything rather than restricting herself to one field, and she enjoys mystery (the Doctor notes that she smiles when hearing something in the lectures she doesn't understand, as opposed to frowning).
  • Blatant Lies:
    • The Doctor hustles Bill away from the puzzling puddle, saying he's bored already with this freaky optical effect.
    • Moira says she's not dating her ex-boyfriend, when she's using his phone to call Bill.
  • Brainless Beauty: Lampshaded when Bill mentions her crush on a beautiful student, "Like a model, only with talking and thinking."
  • Brick Joke:
    • Bill relates a story about how she gave a girl extra chips each day. When the girl finally noticed, Bill noticed she had become fat. During Bill's work montage a few scenes later, she gives extra chips to said girl.
    • The last time the Doctor was undercover in a school he commented that there was a "sinister puddle". Now he's undercover in a school again and there actually is a sinister puddle.
  • Bury Your Gays:
    • Played with. Heather's human self was killed by the Monster of the Week, but it copied some level of her mind to replicate her. The Doctor implies that she is still alive somewhere.
    • Averted with Bill who goes on to become the next companion.
  • Character Title: Heather is chosen as...’The Pilot’s new host.
  • Comically Missing the Point: When the TARDIS starts to shake, Bill finally realises she's not in a room. She's in a lift!
  • Continuity Nod:
    • This is not the first time the Doctor's gone undercover teaching at an educational institution. He was also a caretaker once.
    • It's not the first time that a Time Lord has gone undercover as a university lecturer and maintained that cover for longer than a human academic would manage to do so either.
    • And it's not the first time a companion was stuck serving chips in the school cafeteria.
    • There is a photo on the Doctor's desk of Susan Foreman, his granddaughter and first companion, being present for a good chunk of the First Doctor's tenure, as well as a photo of River Song. There is also a jar of sonic screwdrivers on his desk — apparently every one he's ever had. A statuette of a bird is also prominent on his desk (possibly referencing the raven of "Face the Raven", and/or the "bird" of "Heaven Sent").
    • Bill mentions that the Doctor once gave a lecture on physics that trailed off into something entirely different.
    • The Doctor uses time travel to arrange a secret gift for a companion, as per the red bicycle he got for Rose Tyler.
    • As mentioned below under Red Herring, the Pilot has a number of similarities with various past monsters, particularly the Midnight Creature, the Flood, the ship from "The Lodger" and the Spoonheads.
    • The Fourth Doctor once attempted to explain to his companion Leela why the TARDIS was Bigger on the Inside using a metaphor involving boxes. Nardole explains this to Bill using a (different) metaphor involving boxes, after she finally catches on.
    • The Fourth Doctor's sonic gets used by Nardole to "run interference".
    • And another nod to the Fourth Doctor shows up when the Doctor brings Bill, Nardole and the Pilot to a skirmish between the Daleks and the Movellans!
    • After saying goodbye to Heather, Bill says she's "alright" even though she clearly isn't, which is something the Doctor's done before.
    • As the Doctor is preparing to mind-wipe Bill, Bill resists, asking the Doctor what it would feel like if the same thing was done to him. As she does, the Doctor reacts, and Clara's theme plays. This is also some Reality Subtext regarding the audience reaction to Donna's mind wipe and the Doctor taking matters into his own hands and erasing her memories regardless of how she felt about it and what she wanted. Bill's argument also echoes several of the points made by Clara when she argued against being mindwiped. The fact the Doctor does know what it's like directly references the fact that he took the mindwipe instead of Clara in "Hell Bent".
    • When the Doctor changes his mind about mind-wiping Bill, he tells her to "run!"; Bill's reasoning for resisting the mind-wipe was that she had so few good memories and wanted to hang on to these even just for a day. Part of Clara's catchphrase was "run ... and remember".
    • During the opening scene Bill overhears the Doctor playing a few notes of Beethoven's 5th Symphony on his guitar.
  • Contrasting Sequel Main Character: After his extensive romance with Clara Oswald, the Doctor now has a companion who identifies as a lesbian (as opposed to being bisexual) and their relationship is established from the get-go as strictly professor/student.
  • Dark Is Not Evil: Despite her creepy stare and screams, Heather never attempts to actually harm anyone who doesn't attack her. This is the first hint that she isn't trying to kill Bill.
  • Delayed Reaction: Bill, upon first seeing the TARDIS' interior, assumes that it's a "knock-through" instead of being Bigger on the Inside, and instead compares the shiny metal aesthetic to a posh kitchen as her first remarks. It takes exiting in a completely different location and discovering the box came with them for her to catch on.
  • Double Meaning: The Doctor tells Bill not to be late for her classes as "I'm very particular about time."
  • Double-Meaning Title: "Pilot" is a term often used for the first episode of a TV show, emphasising that this episode is attempting to avert Continuity Lockout, as Moffat has gone on record that the title is a cheeky reference to it. In the meantime the plot revolves around an actual pilot, which turns out to be the Monster of the Week.
  • Driving Question:
    • On an episode-only level: What is the nature of the puddle and Heather's connection to it?
    • On a Story Arc level for Series 10: The Doctor's been teaching at the university for 50+ years as the story begins, and it seems to have to do with the vault beneath the university; what's in it?
  • Eiffel Tower Effect: The Sydney Opera House is used by the Doctor to show Bill and the audience that they have travelled to Australia.
  • Elemental Shapeshifter: The Heather creature spends a lot of time in its original form of liquid.
  • Exact Words:
    Bill: Are you from space?
    Doctor: No.
    Doctor: Nobody's from space. I'm from a planet like everybody else.
  • Exotic Eye Designs: Heather has a heterochromatic defect that gives her a golden five-pointed star on her left iris.
  • Explosive Instrumentation: Nardole sealing off the corridor they're in from the other Daleks by exploding wall panels counts.
  • Eye Motifs: Starting a major motif of Series 10, Heather has a strange, star-shaped flaw in her eye.
  • Failed a Spot Check: Bill, upon first entering the TARDIS, fails to realize it's Bigger on the Inside for quite some time, instead thinking it's a "knock-through" (likely because, in all of the months she's known the Doctor by then, the TARDIS was always parked in a corner). When the Doctor dematerializes it to go to the underground room by the Vault, she thinks it's a lift. She only realizes it isn't when she comes out in a completely new location.
  • Failed Attempt at Drama: The Doctor's first attempt to bring about the Bigger on the Inside reaction from Bill. She just assumes it's a knock-through to a fancy kitchen and asks to use the toilet.
  • Fat Comic Relief: A minor one; Bill had a crush on a girl and gave her extra chips during lunch every day she saw her. This went on for months until Bill realised at one point she had fattened up. (Because of her!)
  • Foreshadowing:
  • Freak Out: After realising she's been instantly transported to Australia, Bill runs for the restroom to splash water on her face.
  • Freeze-Frame Bonus:
    • An eagle-eyed viewer will notice that the Vault is covered in Gallifreyan markings.
    • The Movellans, who were originally seen in "Destiny of the Daleks", are shown to be fighting the Daleks, but only for a second or two.
    • The Doctor's office has numerous props and other items recalling previous episodes. Examples include the Beethoven bust seen in "Before the Flood", a jar full of past sonic screwdrivers, and a figurine of a raven ("Face the Raven").
    • An out-of-universe example: the blackboard the Doctor uses during his lecture is the same prop used for promotional images for the spin-off Class.
  • Genre Savvy: Bill knows enough sci-fi and movies to acclimatise rather easily to what she learns about the Doctor. This is Played for Drama when she realises that he intends to mindwipe her in the denouement.
    Bill: The problem with you is you think nobody's ever seen a movie before! I know what a mindwipe looks like!
  • Genius Bonus: St. Luke, who according to the New Testament was a physician, is the patron saint of doctors.
  • Get Out!: The Doctor says this to Bill after he decides not to wipe her memory because he doesn't want to see her anymore. He changes his mind by the time she's in the courtyard, at least from her perspective.
  • Ghost Butler: Bill tries to pull open the antique metal door to the vault, only to find it locked. Then it opens automatically.
  • Ghostly Glide: When Bill encounters the transformed Heather outside on the university campus, she walks towards her. Heather seems to glide towards Bill in turn, with every step Bill takes.
  • Girly Run: The Doctor's interesting running style is taken note of by Bill — she compares it to "a penguin with its arse on fire".
  • Got Volunteered:
    The Doctor: [tossing him the sonic screwdriver] I want you running interference. Can you do that?
    Nardole: Can I say no, sir?
    The Doctor: No.
    Nardole: Yes, then.
    The Doctor: Thank you.
    Nardole: But not really.
  • Holding Hands: As you do with a companion when you're being chased down a corridor by Daleks.
  • Iconic Item: The Doctor identifies himself to a Dalek by telling it to scan the sonic screwdriver he's holding.
  • Immune to Bullets: Pilot Heather, who is also immune to Dalek laser weapons.
  • Imperial Stormtrooper Marksmanship Academy: The Daleks repeatedly miss the Doctor, Bill, and Nardole. They only hit Heather, who is immune. Later another Dalek misses the Doctor and Bill but turns out to be Heather.
  • Implacable Man: Pilot Heather can travel through space and time just as fast as the TARDIS, and even Dalek weaponry can't harm her.
  • Improvised Weapon: To protect herself against a mysterious intruder, Bill grabs... an umbrella?
  • In Medias Res: In terms of the larger story, a lot of development is skipped over. The episode opens with Bill in the Doctor's office, so she's been aware of his presence for a while and has been attending his classes. His time at the university, in fact, goes back decades, stemming from his need to guard the — at this point entirely mysterious — vault.
  • Insane Troll Logic:
  • Internal Homage: The parallels between Bill and Rose in their introductory episodes are made clear with one shot of Bill waking up in the morning that is a carbon copy of one from "Rose".
  • Intertwined Fingers: With the usual Homoerotic Subtext when Bill mind-melds with Pilot Heather.
  • Jumping-On Point: As alluded to by the title.
  • Jump Scare: The Heather puddle creature tends to do this.
  • Laser-Guided Amnesia: The Doctor attempts to mindwipe Bill at the end, but she figures out what he's up to, objects, and unwittingly reminds him what happened the last time he tried to do that to someone... whereupon he just sends her away.
  • Leitmotif: Clara Oswald's theme is played when the Doctor decides not to wipe Bill's memory. Also, there's a bit of Amy's music ("Can I Come With You?") as Bill begins to grasp the TARDIS.
  • Literal-Minded: Bill asks Heather to promise not to leave while she comes round to see the puddle. The Heather Creature then pursues Bill throughout time and space in order to not leave without her.
  • Living Battery: Heather was needed as a Pilot so the Puddle could leave Earth.
  • Lured into a Trap: The Doctor lures the Heather Creature to the Dalek-Movellan war and into the path of a Dalek's gun, hoping this will destroy it. It doesn't.
  • Making a Splash: The Heather creature can't actually control water but becomes liquid.
  • Mind Rape: The Doctor tries to mindwipe Bill in the denouement, as he doesn't want others to find out what he's up to, but gives in to her objection to it.
  • Morality Chain Beyond the Grave: Just as the Doctor is about to wipe Bill's memory, Clara Oswald's Leitmotif begins playing and he relents, recalling the events of "Hell Bent" (in which it's established that the Doctor remembers everything that happened with Clara... he just doesn't clearly remember Clara anymore).
  • Morphic Resonance: When Heather becomes a Dalek, the eyestalk has her eye with the star.
  • Motifs: Several specific to this series are introduced here.
    • Mothers: Bill never knew her birth mother, nor has any pictures of her. The Doctor arranges for her to have some...
    • "Villains" who aren't evil: The Heather Creature, once possessed, just wants companionship.
    • Imprisonment/Release: The Doctor and Bill realize that the only way to stop the Heather Creature is for the latter to free it of her promise to not leave without Bill, and she does so.
    • Hidden threats: The puddle turns out to be sentient starship fuel... and it needs a pilot.
    • Exploitation: The puddle takes over Heather's body and mind.
    • Promises: See The Promise below.
  • Mundane Utility:
    • The Doctor gets a loud squeal from his electric guitar, so he adjusts it with the sonic screwdriver.
    • When Bill talks of how she has no photographs of her mother, Moira mysteriously finds an entire box of photos of Bill's mother in a cupboard. Then Bill sees in one of the photographs a reflection of the photographer — it's the Doctor, having apparently gone back in time and taken them all as a Christmas gift.
  • Murder Water: The Puddle, which drags Heather in. The Heather Creature then proceeds to pursue Bill, but subverted when it turns out it doesn't intend her harm.
  • Mythology Gag:
    • The Doctor hiding out in a English university as a professor to guard an alien artefact is something his mentor Professor Chronotis did in Douglas Adams' story "Shada", the one incomplete serial of the original series.
    • Bill is named as an homage to William Hartnell (the First Doctor, who was known as "Bill" to friends and relatives), and the girl she has a crush on, Heather, is named after Hartnell's wife, Heather McIntyre.
    • Bill's idea that the TARDIS' police-box exterior is a "knock-through" (i.e. the box conceals a hole in the wall that leads to another, larger room) is a riff on Ian's rebuttal to Bigger on the Inside in the novelization of "The Daleks": when he first stepped through the box, he thought he'd fallen into a cellar that the Doctor had "dressed with gadgets to fit [his] story." It also refers to the fact that many homemade TARDISes over the years have been designed this way.
  • Nigh-Invulnerable: Heather, or whatever the alien posing as her is, can shrug off the most powerful fire in the universe: Dalek weaponry.
  • No-Sell: A Dalek repeatedly fire on Heather, but the shots just pass through her while she parrots its cries of "Exterminate!" Then she either destroys or absorbs it off-screen.
  • Non-Malicious Monster: Heather doesn't want to hurt Bill, she's just trying to fulfil the promise not to leave without her.
  • Noodle Incident: Nardole hates going to the planet where the trio encounter Daleks and Movellans. The planet isn't actually identified.
  • Offscreen Teleportation: Justified; Bill flees when the Doctor tells her to Get Out!, only to find him waiting outside next to his TARDIS.
  • Oh, Crap!:
    • Nardole thinks that losing the Pilot by making it fly through somewhere dangerous is a good idea. Until the Doctor points out that means they've got to fly through there first. He's even less happy when presented with specifics.
    • Bill hears someone running the shower and assumes it's her foster mother, until Moira calls from a bar she's at. So who's in the house with her?
  • Parental Neglect: While Bill's foster mother isn't a Wormwood-level abusive anti-intellectual, she's still rather apathetic about her "daughter": she dismisses a stack of high-scoring assignments (Bill only just started taking college-level courses) and worries Bill is getting involved with her new older male mentor (Bill's a lesbian), doesn't think too much about the discovery of a huge pile of photos of Bill's biological mother (Bill only had one picture and zero memories of her), and gives her two very old £10 notes as a Christmas present (Bill got her a fancy scarf, which she claims the cash will just about cover; at least the envelope was nice).
  • Powered by a Forsaken Child: The Puddle, in order to leave Earth, needs a human pilot.
  • The Promise:
    • Heather promises not to leave without Bill before the Pilot takes her over — thus, Pilot Heather stalks Bill.
    • The Doctor made a promise to someone that appears to not only preclude him taking on Bill as a companion but also necessitate wiping her memories of him in the denouement. Said promise seems to be related to the mystery of what's in the vault beneath the university, which has apparently kept him and Nardole tied down to it for 50+ years. But Bill unwittingly reminding him of his final separation from Clara convinces him to spare her the mindwipe, and from there he decides to take her on as a companion, literally saying "What the hell."
    • Nardole is making good on his own promise to ensure the Doctor is all right, even if it means he has to "run interference" to deflect a bunch of battle-hyped Daleks' attention.
  • Pull the Thread: Bill wonders how the TARDIS got inside the room as the door's too small. When the Doctor claims it was lifted through the window by a crane, she later notes that the rug she gave him is now partially underneath the TARDIS, despite it being heavy enough to require a crane to lift.
  • Red Herring:
    • For the audience: The Monster of the Week has attributes we've seen before: Mimicry like the Midnight Creature and the Spoonheads, constantly pouring water like the Flood, seeking a pilot like the ship in "The Lodger". In fact, it's something entirely new, and it isn't actually evil as those were. Even the Doctor doesn't realize Pilot Heather's true intentions for a while, possibly because he recalls those previous experiences and others!
    • Heather's Exotic Eye Designs: The Doctor stated he'd never heard of a defect that can cause such a shape and Bill thinks it might be a sign Heather's possessed. As far as it's shown in the episode it's just a "deformity".
  • Releasing from the Promise: Bill realises that she has to do this to stop Pilot Heather, since the last thing she asked Heather before Heather fused with the puddle completely was not to leave without her.
  • Reveal Shot: The Doctor enjoys Bill's flustered reaction on realising they've travelled from a college cellar at night to a city in broad daylight, then steps aside to reveal the Sydney Opera House.
  • Riddle for the Ages:
    • Where did the spaceship that leaked the puddle come from, who/what operated it, and why did it land at St. Luke's? This question is never answered — not in this episode, not in the remainder of the season, and not in the Twelfth Doctor's Grand Finale "Twice Upon a Time". Unless a future Doctor visits St. Luke's the question will likely never be approached again!
    • It's also not shown how the Doctor got his lengthy tenure at St. Luke's in the first place, though given his association throughout history with Britains' powers-that-be it's no surprise either.
  • Robotic Reveal: Nardole sounds quite creaky when he is first shown, and when he extends his hand to Bill a bolt falls out of his arm, which he attempts to cover up. It better explains just how Nardole is (or at least looks) whole again after a Hand Wave in the previous episode.
  • Secret Test of Character: All of the Doctor's interactions with Bill appear to be him sounding her out as a potential companion. Nardole needles him for this in an early scene.
  • Sequel Hook:
    • Bill hopes to find Heather again and perhaps save her.
    • Also, the question of who owned the shuttle that left behind the shapeshifting engine oil that possessed Heather, and if they were looking for the Doctor's vault.
  • Set a Mook to Kill a Mook: The Doctor goes to the Dalek-Movellan war, and leads the Heather Creature into the path of Dalek fire in an attempt to kill it. It doesn't work.
  • Shadow Archetype: There's an uncomfortable similarity between the Pilot and the Doctor. Both are nameless, human-looking yet potentially dangerous aliens who tempt Bill from her boring life by showing her the wonders of the universe.
    The Doctor: Bill, listen to me. Whatever she's showing you, whatever she's letting you see. It's a lure, it's a trap. She's making you part of her, and you can never come back.
  • Shout-Out: Pilot Heather comes out of the mirror in Australia like the face thing in The Abyss.
  • Single Tear: After rejecting the Pilot's offer to join her in exploring the universe, Bill brushes a tear from her eye, but then comments that it's likely not hers.
  • Snark-to-Snark Combat: Averted; Nardole waits for a comeback from Bill after the Doctor makes a snarky comment about students. She just looks hurt.
  • Stalker with a Crush: Heather, the titular Pilot, stalked Bill throughout space and time — though she leaves when Bill says that she has to let her go.
  • Stealth Hi/Bye:
    • The Doctor pulls one on Bill in his office when she tells him about the puddle. She's looking out the window as she speaks, and she suddenly notices him running by outside. When she turns around his chair is still spinning.
    • Bill tentatively opens the door to the bathroom to find the bathtub and shower empty, yet still wet.
  • Subverted Catchphrase: Bill does the "Doctor what?" version. The Doctor looks miffed. She also repeatedly fails to get what's up with the TARDIS, first thinking it's a fancy kitchen, then a knock-through, then a lift, then capable of going "anywhere in the university".
    Doctor: Is it my imagination, or is this taking longer than normal?
  • Summon Bigger Fish: The Doctor goes to the Dalek-Movellan war, hoping that the Daleks will destroy the Heather Creature.
  • Super-Persistent Predator: Pilot Heather is able to track Bill anywhere and anywhen in the universe in order to keep the promise she made.
  • Swiss-Cheese Security: The door to the vault is set to Friends Only. Thus enabling Bill to sneak in to see what the Doctor and Nardole are up to. "Personal student" must be close enough.
  • Symbiotic Possession: The puddle that takes over Heather enables her to leave as she wants, and she retains enough of her free will to try and take Bill.
  • Time Skip:
    • The Doctor and Nardole have been at the university for either 50 or 70 years, implying it has been at least this long since the events of the preceding episode.
    • In the episode itself, there are multiple as it takes place over the span of most of an academic year, beginning in the autumn and ending in the spring.
  • Timey-Wimey Ball: Bill finds herself in a futuristic war, and asks if they're travelled forward in time. The Doctor says they've actually travelled into the past. His past, of course.
  • Toilet Humour: When Heather explains that the “puddle” can’t be rainwater, since it hasn’t rained for a while, Bill notes that half of the campus are boys, a non-too subtle piss joke.
  • Touched by Vorlons: Subverted. The star-shaped mark in Heather's eye looks like the sign of some kind of alien influence, and Bill even guesses this might be the case, but it turns out to just be a strange manifestation of heterochromia.
  • Try and Follow: The Doctor takes the TARDIS to Australia, then 23 million years in the future on the other side of the universe, then into the midst of a Dalek war to see if the Pilot will follow. It does.
  • Uncanny Valley:
    • In-Universe, anyone who looks into the puddle is gobsmacked by what they believe to be their reflection looking back, seeing something they can't put their finger on as wrong. It isn't until later that the Doctor deduces it's because it isn't a mirror image but a mimicking copy.
    • Also In-Universe when Bill encounters Heather after her mysterious disappearance. She slides across the lawn without moving her feet, can only repeat Bill's words, and gushes a lot more water than she would if she was just wet.
  • What, Exactly, Is His Job?: Bill notes that nobody is quite sure what the Doctor teaches, as he's allowed to lecture on whatever he wants and doesn't even keep to his own lesson plan.
  • What the Hell, Hero?: Bill calls out the Doctor for not only trying to mind-wipe her, but also assuming she wasn't smart and Genre Savvy enough to figure out what he intends to do.
  • The World Is Just Awesome: Bill sees the universe on mind-melding with the Pilot. The Doctor does a verbal version during one of his lectures.
    The Doctor: Imagine if time all happened at once. Every moment of your life laid out around you like a city. Streets full of buildings made of days. The day you were born, the day you die. The day you fall in love, the day that love ends. A whole city built from triumph and heartbreak and boredom and laughter and cutting your toenails. It's the best place you will ever be.
  • You Remind Me of X: A subtle version — when Bill asks the Doctor why he's picking on her, out of all the people who come to his lectures who aren't supposed to, he glances at the photograph of Susan. "Well, I noticed you."

Bill: What changed your mind?
The Doctor: Time.
Bill: Time?
The Doctor: And Relative Dimension In Space. It means, what the hell?