"I saw the Fall of Troy! World War Five! I was pushing boxes at the Boston Tea Party! Now I'm gonna die in a dungeon... in Cardiff!"The first episode Mark Gatiss wrote for the TV series, based loosely on his Big Finish Doctor Who episode "Phantasmagoria". Also, as the episode is set at Christmastime, the closest thing Christopher Eccleston has to a Christmas special on Doctor Who, even if the seasonal festivities are in name only.The Cardiff rift remains open, and becomes a major feature of the Whoniverse from this point on.
— The Doctor
The Doctor tries to take Rose to Naples, 1860. The TARDIS disagrees, and instead takes them to Cardiff, Christmas 1869.Charles Dickens is in town, prompting an outbreak of earnest fanboyishness from the usually sardonic Ninth Doctor. The squee doesn't last — the dead are walking, so the Doctor springs into action. It turns out that there's a massive space/time rift right in the middle of Cardiff. This will become important later. A young psychic maid named Gwyneth can guide things through the rift.Dragging the very skeptical Dickens along, he organises a seance and negotiates with the aliens. If he helps them through the Cardiff Rift, they can temporarily occupy some corpses until he finds them a better home. Rose is Squicked, but the Doctor isn't in the mood to listen to some silly little human and coddle her delicate sensibilities.The Gelth (as they call themselves) prove to be a bunch of lying promise-breakers, being "a few billion" in number and not being almost-dead. They were bent on wiping out humanity and taking over their corpses. The Doctor shows his raging Survivor Guilt over having previously killed a few species, most recently his own, and hesitates to jump into action. Gwyneth takes the decision out of his hands by sacrificing herself. Charles Dickens learns an important lesson about Christmas, and merrily bids the Doctor farewell, planning to include all sorts of ghosts and blue lights and aliens in police boxes in his novels from now on. The Doctor gloomily notes that nothing will actually change, though, because Dickens will be dead of natural causes within a year.
- Aliens in Cardiff: The first appearance of the Cardiff Rift.
- Arc Words:Gwyneth: (to Rose) The things you've seen. The darkness. The Big Bad Wolf.
- Attending Your Own Funeral: One of the Gelth-possessed corpses did exactly this.
- Blatant Lies: When Rose confronts Gwyneth, she claims the old lady is suffering from "a brain fever", when said old lady is stone dead. Rose doesn't buy it for a second.
- Bottle Episode: The previous episode "The End of the World" spared no expense as it was meant to retain viewers who had followed from the premiere. This episode was filmed in the same block as "End of the World", and while there are special effects, note how this episode is a Period Piece to save money by using the BBC's already existing sets and costumes without having to create any.
- Can't Argue with Elves: Or, in this case, with the Doctor.
- Changed My Jumper: The Doctor makes Rose change into something less distressing to Victorian sensibilities but makes no changes to his own outfit except a new jumper. Nobody but Dickens remarks on the Doctor's attire and he merely thinks the Doctor is just some navvy (laborer).
- Christmas Episode: Takes place on Christmas Eve, but very little Christmassy happens apart from Dickens having a Scrooge-like rejuvenation.
- Condescending Compassion: Rose is sympathetic towards Gwyneth for her sad lot in life, and tries to give her advice on how to improve her situation. Except that Gwyneth doesn't feel her lot in life is particularly sad, and is insulted by the insinuation. Softened somewhat by the fact that Gwyneth can read Rose, and understands that this is simply due to Rose's background being fundamentally different from hers.
- Dead All Along: Gwyneth convinces the Doctor to leave so that she can stop the Gelth. The Doctor checks her pulse and escapes before she ignited the gas in the parlour. He later informs Rose and Charles Dickens that Gwyneth had been dead for several minutes.
- Dirty Old Man: Rose claims Mister Sneed felt her up while loading her onto the hearse.
- False Innocence Trick: The Gelth claim to be refugees from the Great Time War who have lost their bodies and only want to use dead humans as Meat Suits. It turns out that there are many more of them than they claimed, and they want to take over all humanity, not just the dead ones. Granted, they're not actually lying — the key here is that they just need dead bodies. A few billion. Which means a majority (if not all) of the human population of Earth at the time.
- Foreshadowing: The Doctor and Dickens talking about The Signal-man and A Christmas Carol.
- Ghostly Chill: The morgue cools down when the Gelth appear.
- Great Offscreen War: The Gelth mention that the Time War wasn't visible to lower species, but it was to anyone sufficiently advanced enough, like themselves.
- The Greatest Story Never Told: Rose laments that no-one will ever know what Gwyneth did.
- Heroic Sacrifice: By Gwyneth to sabotage the Gelth.
- Historical-Domain Character: Charles Dickens
- Historical In-Joke: Dickens declares his intention to incorporate the Gelth into the climax of The Mystery of Edwin Drood, a novel that famously went uncompleted due to Author Existence Failure.
- I Was Just Passing Through: The Doctor claims this when Dickens inquires as to his true identity.
- The Knights Who Say "Squee!": The Doctor squees at learning he's sitting next to Charles Dickens.
- Lame Pun Reaction:The Doctor: Don't antagonise her. I love a happy medium.
Rose: I can't believe you just said that.
- Newspaper Dating: How the Doctor figures out the TARDIS didn't land in Naples.
- Ominous Fog
- Psychic Powers: Gwyneth
- Puppeteer Parasite: The Gelth.
- Rebel Relaxation: The Doctor, while watching Dickens check out a corpse.
- Red Eyes, Take Warning: You know the Gelth aren't what they claim when the one speaking through Gwyneth changes from a soothing uniform blue to having red eyes.
- She Cleans Up Nicely: Rose dons period-appropriate dress for the eighteen-hundreds. The Doctor notices, before adding "considering".
- Spooky Seance
- Stealth Pun: "What the Shakespeare?!" said by Charles Dickens.
- Temporal Paradox: Rose thinks that this means the Gelth can't kill her in 1869, since she's still living in 2005. As the Doctor explains, however, time travel doesn't work that way — her travel from 2005 to 1869 doesn't affect her ability to die.
- Victorian Britain: Cardiff, 1869.
- Wham Line: "Maybe your dad's up there too, miss" is one for Rose. She didn't mention her father at any point to Gwyneth.
- White Man's Burden: Subverted. In a temporal socio-economic version of the trope, Rose takes pity on Gwenyth and tries to stop the Doctor from "using" her to let the Gelth through. Gwyneth does not appreciate this, accusing Rose of thinking that she's stupid and unable to understand what is going on just because she didn't have an education.
- World War Whatever: The Doctor mentions having seen World War V.
- Yet Another Christmas Carol: Downplayed, but the elements are still there; adventures with ghostly creatures and time travellers help shake Charles out of his ennui.