"The world doesn't end 'cos the Doctor dances."The Doctor, Rose and Jack desperately try to escape the gas mask people and figure out what the hell is going on. While Jack teleports away, Rose and the Doctor are trapped for a while, and Rose takes the opportunity to ask the Doctor if he can dance like Jack can. The Doctor is a bit offended, and says he's actually got quite an amount of experience with... dancing. Rose really can't picture him... dancing. While the Doctor steps closer and takes her hands for an intense... dance, they fail to look around and realize that Jack's already saved them. It also turns out that Jack isn't exactly with the Time Police any more; he turned rogue after waking up one morning and finding that two years of his memory had been wiped by his employer.Jack goes off to distract a gay crash site guard with his suave, omnisexual allure, and the Doctor explains to Rose that Jack is, quote, "just a bit more flexible when it comes to... dancing". In Jack's century, people will travel the whole universe to find aliens of all sexes and genders, and... dance with them. Meanwhile, the virus becomes airborne and everyone around the warship crash site starts mutating.Seeing the crash site, the Doctor figures it out: the Chula warship was a field ambulance,note and contained nanobots (here called "nanogenes") for expedient battlefield healing. When Jamie was first hit by the ship, the nanogenes swung into action and tried to fix him... but they'd never interacted with humans before, and so derived their idea of what humans looked like from a badly wounded kid in a gas mask. They sort of made it up as they went along — assuming that fully healed people wore gas masks, they made the people they "infected" sprout gas masks. But when they finally met Nancy (really Jamie's mother, not his sister), they had a different model of a healthy human being to work towards... and the parent/child relationship between the subjects meant that the nanogenes knew that this pattern was the right one.Everybody Lives as the Doctor re-infects everyone with the nanogenes, who now know how to fix humans. Even previously dead humans. Hooray! It goes better than expected, because at least one person grows their whole leg back, so it's safe to say everyone even got their war wounds reversed. Jack uses the Chula ship to suspend the dropping of the bomb that was supposed to blow up in the location the Chula ambulance crashed, "Schlecter Wolf" (Roughly translated as "Bad Wolf"- Arc Words strike again!) He flies off into space.The Doctor decides the evidence of an alien race needs to be wiped out to keep history sterile. He makes the Chula ambulance self-destruct when the area is clear of people, reasoning, "History says there was an explosion here. Who am I to argue with history?" with Rose replying, "Usually the first in line."The Doctor and Rose return to the TARDIS, with the Doctor apparently knowing what Rose wanted for Christmas when she was twelve and having a part in getting it. But mostly ecstatic that everybody lived... until Rose wonders what happened to Jack.Jack Harkness is flying through space in his handy Chula Ship, but he only delayed "Schlecter Wolf" from its volcano day. The WWII bomb is about to go off, and Jack cannot stop it from blowing him and his ship into space dust. After bickering with the A.I. of his ship under the false hope there might be an escape pod somewhere, he is repeatedly told not so, until the A.I. flatly spells it out for him that he is 100% doomed. Resigned to his fate, he orders an Emergency Protocol 147- a martini... with too much vermouth. Jack is going to drink to his own death and go out with a bang, reminiscing about the time he got out of it before by charming his executioners into bed with him...Cue the faint sound of vintage swing music from afar. The TARDIS has docked to Jack's ship long enough for him to cross over and let the bomb wipe out the last trace of the Chula civilization without him on board. The Doctor has given him a lift after Rose's concerns set off the alarm bells in his head to pick up Jack so the bomb won't get him. He tells Jack to hurry up and get in the TARDIS, but to also shut the door- there will be quite a draft when the explosion strikes. Needless to say, Captain Jack joins the TARDIS, saved by the Doctor just before his ship goes kablooey in an attempted Heroic Sacrifice. He walks in to find the Doctor and Rose... dancing. Rose asks if Jack would like to cut in and also... dance. The Doctor, amused to have an openly not-straight companion, wonders which of the two Jack would... dance with.
— Rose Tyler
- America Saves the Day: Despite taking place in 1941, and thus mere months before the US would join World War II and come to Britain's direct aid, the most obvious use of the trope is never discussed. On the other hand, Rose seems confident enough that the swaggering well-equipped (fake) American (from the distant future) will come through that she insists on the Doctor taking a break for a bit so they could dance.
- Arbitrary Skepticism: Discussed TropeNancy: You just told me that was an ambulance from another world. There are people running round with gas-mask heads calling for their mummies and the sky's full of Germans dropping bombs on me. Tell me, do you think there's anything left I couldn't believe?
- Arc Words: "Schlecter Wolf", a "Blind Idiot" Translation of "Bad Wolf", on the bomb Captain Jack rides at the end. This was a last minute addition, as Moffat hadn't been told about the arc.
- An Arm and a Leg: Inverted. Mrs. Harcourt, one of the victims of the nanogenes, had her leg grown back by them.
- Author Appeal: This episode is pretty much Steven Moffat's love letter to shipping, and a manifesto on how he refuses to see the Doctor as asexual (as many fans, for some reason, do). It also marks the start of the Doctor Who TV series being completely inclusive of LGBTQ culture (which the novels had already been since the late '90s).
- Autodoc: It turns out that this is what the Chula warship is.
- Awesome, but Impractical: Jack's flashy sonic blaster turns out to be this; it looks good on the surface and has all sorts of cool features, and leads both him and Rose to make some slightly snide comments about the Doctor's much-less impressive seeming sonic screwdriver. But it turns out that all those cool features run the battery out really fast and it's very quickly next to useless... unlike the Doctor's trusty sonic screwdriver. This is part of a direct comparison between Jack, who seems like a perfect sci-fi hero but quickly reveals himself to have feet of clay and to be completely out of his depth, and the Doctor, who seems a lot more eccentric and unusual but ultimately can get the job done.
- Bavarian Fire Drill: The Doctor gets all the gas-mask people to leave them alone by acting like a stern mummy and telling them to "Go to [their] room!" Comes back to bite the Doctor when he realizes he, Jack, and Rose were standing in the child's room when he gets there.
- Blackmail: A homeowner catches Nancy stealing food and threatens her with the police. Nancy isn't cowed in the slightest, and imperiously demands that the homeowner give her some tools she needs, on the grounds that she knows it's him, not his wife, who's been trading sexual favors for extra rations from the local butcher.
- Bullethole Door: Well, Squareness Gun-hole door. Also used on the floor once.
- Call Back: Adam isn't mentioned by name but the Doctor is not fond of Jack at first, and this is before he realized Jack's full involvement in the plot. He asks Rose where she picked Jack up.
- The Virus responsible for the plague turns out to be the same kind of nanogenes used to fix up Rose's hand in the previous episode.
- Chekhov M.I.A.: Jamie's mummy.
- Computer Voice: Jack's ship has a female one, telling him the exact odds of his survival.
- Creepy Child: Jamie; quite possibly the creepiest child since Billy Mumy in The Twilight Zone.
- Dance Party Ending: In the TARDIS. The only question is who will Jack dance with.
- Death Glare: The Doctor to Jack, multiple times, until he finally admits that it's all his fault and tries to make up for it by way of Heroic Sacrifice.Jack: Getting a hint of disapproval.
- Death Is Cheap: The nanogenes can revive the dead. As the Doctor puts it, "what's life, but nature's way of keeping meat fresh."
- Double Entendre:
- The Doctor mentions that he's got a sonic tool, but he tries to avoid telling Jack what it is, because his tool isn't as impressive as Jack's.
- At the end, when Capt. Jack Harkness is transported to TARDIS, he makes a remark about it being Bigger on the Inside, upon which the Doctor responds with "You'd better be."
- Double Meaning: Jack swears several times that the Chula ship was "empty". He was wrong, but given that Jamie is described several times as empty, he's sort of right by extension without realizing it.
- Everybody Lives: Trope Namer! Just this once, Rose, Trope Namer!
- Exact Words: Jack's Chula warship is an ambulance. They have ambulances in wars.
- Extreme Omnisexual: While the episode before this one hinted at it this episode confirms that no, when it comes to sex, Captain Jack Harkness does not care about your gender or even your species. It's also stated that most people from the 51 century are like that. Which builds on Cassandra hinting in the second episode that there are no more full blooded humans by the year 5 billion, but there are a lot of human-like species.
- Face Death with Dignity: Jack seems very comfortable awaiting his death once he learns escape isn't possible. He orders a drink and reminisces about past adventures.
- Family Relationship Switcheroo: Nancy claims the Creepy Child to be her brother but it turns out to be her son. He is only healed of his zombification after Nancy admits to him that she is his mother, and the nanogenes recognize the literal "mother genes" and heal him and everyone else based on their new knowledge.
- Famous Last Words: Lampshaded by the Doctor. "Go to your room!" would be very bad last words.
- Locked in a room with a panicked infected soldier, Nancy is able to calm him down and put him to sleep by singing lullabies, as a mother would do for her child.
- Earlier, the room where Jamie was kept was covered with crude drawings of him and his mother. Noticeably, there is no sign of his "older sister" in them.
- Getting Crap Past the Radar: Try bleeping out every use of "dance".
- Going Critical: Not in the story proper, but the reactor at the factory Jack got his gun from went critical.The Doctor: (identifying Jack's weapon) Sonic Blaster. Fifty-first century. Weapons factory at Villengard?
Jack: You've been to the factories?
The Doctor: Once.
Jack: Well, they're gone now, destroyed. Main reactor went critical, vaporized the lot.
The Doctor: Like I said. Once.
(looking over at Rose; matter-of-factly)
The Doctor: There's a banana grove there now.
(looks at Jack; smiling)
The Doctor: I like bananas. Bananas are good.
- Gone Horribly Right: The Doctor opens the episode by treating the Empty Child as a bad boy, and sending him to his room. Later on, the Doctor visits the laboratory that acted as Ground Zero for the Empty Child's plague, only to realize that this is his room.
- Heroic Sacrifice: Attempted and averted. Jack was willing to die with a smile on his face drinking a martini as the bomb was about to explode when the Doctor saves him.
- The Home Front: London during the Blitz.
- It Was with You All Along: The nanogenes could've cured Jamie from the get-go had Nancy just given him a hug.
- Laser-Guided Amnesia: Captain Jack cites this as being the reason he left the Time Agents: two years of his life mysteriously deleted.
- Luke, I Am Your Father: Jamie, I Am Your Mummy. It turns out Jamie's not Nancy's brother — he's her son. Nancy deliberately lied to people about having a child that young and out of wedlock, and given how young she looks and the current state of Britain, no-one would question it. "I will always be your mummy..."
- Nice Job Breaking It, Hero: Jack is incredibly flippant about things throughout the entire episode, until the Doctor finally realizes what's happened, and that it's the nanogenes from the ship that Jack very carelessly sent careening to Earth which are causing all the trouble. The Doctor then makes a point of explaining to Jack in very precise and no uncertain terms exactly how he's just gone and doomed the entire human race, with a look of barely-restrained fury and disgust on his face the whole time. Jack looks a lot less flippant at that point.
- Noodle Incident:
- While waiting for the bomb to explode, Captain Jack recalls the last time he was sentenced to death. He ordered four Hyper Vodkas, and woke up in bed with both his executioners. They stayed in touch afterwards.
- The Doctor is implied to be somewhat responsible for the destruction of the weapons factory on Vilengard.
- Non-Malicious Monster: The child and his bodies, again, and the nanogenes were just trying to help; they just had a really bad template.
- Not Distracted by the Sexy: Defied. Rose expects she's going to be the one who has to distract the soldiers guarding the ambulance, but Jack notes that he knows the guy in charge and she's "not his type".
- Oh Crap!:
- The Doctor realizing that he'd sent the boy to his room... the room they were in.
- Along with that, they are playing back tapes of Jamie in the hospital repeating things about his mummy. Then they realize they are still hearing Jamie even though the tape ran out.
- Also Jack, once he realizes that he's to blame for the entire situation and has probably doomed Earth.
- The soldier who is meant to watch Nancy is panicking as she makes him realize this isn't just some cough as he cannot remember his wife's name, any children they have, or even his own name.
- The Doctor realizing that he'd sent the boy to his room... the room they were in.
- Older Than They Look: A plot point for Nancy, who looks young enough to blend in with a group of orphans but is actually (just barely) old enough to really be Jamie's mother. The actress really was the age of the character too, despite being able to pass for 13 or 14.
- One Last Smoke: Or One Last Drink — Emergency Protocol 417. A Martini. With too much vermouth. Luckily for Captain Jack, he's saved by the Doctor and Rose.
- Phlebotinum Breakdown: Jack's "Squareness Gun" doesn't work when it is needed most.
- Riddle for the Ages: Jack's memory loss was never explained, although in Torchwood, we do get to meet a fellow Time Agent.
- Riding the Bomb: Cap'n Jack. He even teleports onto it to be able to talk with the Doctor and Rose.
- Room Full of Crazy: Belonging to the original patient, plastered in doodlings of "mummy".
- Screw Destiny: Averted. The Doctor notes history said a bomb went off where the Chula ship fell, so he was going to set it to self-destruct. Who is he to argue with History? Rose notes, normally he's first in line.
- Sexy Man, Instant Harem: Jack.
- Continuing the Star Trek from last episode, with the Doctor still known to Jack as "Mr. Spock".
- And, in light of the earlier Spock references, the computer quoting the odds of survival to Jack near the end probably counts too.
- Snub by Omission: After Jack teleports out, Rose asks why it's always the great-looking ones who vanish into thin air.The Doctor: I'm making an effort not to be insulted.
- Stuff Blowing Up: The Doctor's MO.Rose: First day I met him, he blew my job up! That's practically how he communicates.
- Super Soldier: The victims of the nanogenes become this.
- Title Drop: See the page quote.
- The Virus: Actually nanogenes.
- Weirdness Magnet: Albion Hospital was also home to an "alien" pig.
- We Need a Distraction: Rose offers to do this, only for Jack to explain she's not the guard's type.
- World War II: The time of the episode's setting.
- "Everybody lives, Rose. Just this once, EVERYBODY LIVES!!"