Rose: Doctor, they've got guns.
The Doctor: And I haven't. Which makes me the better person, don't you think? They can shoot me dead, but the moral high ground is mine.
The episode begins with a voice-over of Rose recounting that nothing happened the first nineteen years of her life, but that it changed when she met the Doctor, with whom she thought she'd travel forever. She then talks about ghosts, Torchwood and the war, and says that the story she is telling is of how she died.
The TARDIS shows up in a park near Jackie's flat so that Rose can visit her mother and do some laundry (apparently the TARDIS lacks a washing machine). Jackie greets them and asks if they want to stay and see her visiting father, which confuses and concerns Rose, as her grandfather died when she was ten. An insubstantial grey "ghost" appears and Jackie introduces it to Rose and the Doctor. The concerned Doctor finds out from watching television that this is happening all over the world, and with Rose and an unwilling Jackie in tow quickly traces the source of the "ghosts" to a building that houses the Torchwood Institute, a secret British government organization with a mandate of protecting the United Kingdom and Earth at any cost (originally conceived by Queen Victoria after her encounter with the Doctor in 1879
It is Torchwood who are causing the "ghost shift" as they try to tap into a source of extra-dimensional energy. They also show the Doctor a mysterious globe that he informs them is a "void ship", a craft designed to travel the non-existent space between parallel dimensions. The Doctor tells the head of Torchwood, Yvonne Hartman, that the void ship's entry into the Earth dimension damaged the barrier between universes, and that each time they activate a ghost shift, they are damaging it further, which will eventually cause the barrier to collapse. She reluctantly agrees to delay the next ghost shift, but several technicians have been taken over by Cybermen from the parallel universe of "Rise of the Cybermen"
/"The Age of Steel"
and activate it anyway.
This brings some 5,000,000 Cybermen across the dimensional gap all over the world, even inside Torchwood, where they begin changing the operatives, including Yvonne, into Cybermen. In the void ship room Rose meets Mickey, who has also crossed the dimensions, and they watch as the void ship begins to open. Mickey tells Rose that the Cybermen left their original dimension some time ago, then hoists a weapon designed to kill them, only to stare in disbelief with Rose as four Daleks emerge from the void ship.
Dalek Sec: Location: Earth. Life-forms detected! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE!
- Affably Evil / Benevolent Boss: Yvonne "If it's alien, it's ours" Hartman takes care to remember the names of her employees and doesn't bat an eye at office romances ("And they think we haven't noticed").
- An Astral Projection, Not a Ghost: The "ghosts" are actually Cybermen trying to break through from Pete's World.
- Benevolent Boss: For all Yvonne is a specist, imperialistic sort, she is benevolent toward her underlings, making a point of knowing their names, and not objecting to two of them slipping out to "double-check the readings".
- BFG: Mickey has one stored in the Void Ship room.
- Bollywood Nerd: Doctor Rajesh Singh
- Brutal Honesty: No, Jackie, the Doctor does not think dead relatives coming back is beautiful. In fact, it's horrific.
- Catch Phrase: "I should say 'Allons-y' more often..." He will, but he won't find anyone called "Alonso" to say it to for a while.
- Call Back:
- The way the Cybermen hiding in Torchwood reveal themselves is a homage to the way the Mondas Cybermen clawed their way out of their pods in "Tomb of the Cybermen".
- That sarcophagus at Torchwood looks... somewhat familiar.
- A more recent example: one of Torchwood's Void gate technicians is Gareth.
- The "stay away from the scary humans" line The Doctor said back in the pilot has come true. Yvonne says that Torchwood shoots down any aliens that come into their airspace whether they're hostile or not.
- Composite Character: Yvonne Hartman is a combination of Yvonne Hartley and Doctorman Allan, from the Big Finish Doctor Who episode "Spare Parts".
- Continuity Nod: The Gelth from "The Unquiet Dead" are mentioned as a possible explanation for the ghosts.
- Critical Research Failure: Yvonne quotes energy readings in Gigawatts at one point. The Watt is a measure of power, not energy.
- Deadline News: "They're not ghosts! They're metal men-AAAGH!"
- Death by Sex: Two minor characters end up stumbling into the Cybermen's hiding place in Torchwood Tower while looking for a place for a quickie.
- Doing In the Wizard: Humans are convinced that their loved ones are returning as ghosts. The Doctor is convinced there's a scientific explanation. Of course, the Doctor is right.
- Eldritch Starship: Anyone who looks at the void ship feels there's something unnatural about it.
- Everyone Can See It: The two Torchwood employees in a relationship.
- Evil Versus Evil: Cybermen versus Daleks.
- The Exit Is That Way: "No, Doctor!"
- Foreshadowing: For Big Finish fans, the name "Yvonne Hartman" was a rather clever bit of foreshadowing for the arrival of the Cybermen: her name is based on Yvonne Hartley, from the episode "Spare Parts".
- Also, the bluetooth earpieces that all of Torchwood's personnel have. The last time we saw people wearing earpieces was in the Rise of the Cybermen/The Age of Steel.
- The Doctor thinks the idea of loved ones coming back to life is horrific. We don't learn why until the Tenth Doctor's very last episode.
- The news announcer talking on the "Ghostwatch" segment mentions the regular gatherings of ghosts around Westminster Bridge, almost like a military display...that's because it is.
- From Bad to Worse: Okay, there's an army of five million Cybermen spread across the whole world. What next? Daleks!
- Internal Homage: Yvonne Hartman's name, to Yvonne Hartley from the Big Finish Cyberman episode "Spare Parts".
- I Will Show You X: Also counts as a Running Gag, since twisted ankles were the #1 cause of trouble in the earliest Doctor Who stories.
Doctor: Lead on. But not too fast. Her ankle's going.
Jackie: I'll show you where my ankle's going.
- Let Us Never Speak of This Again: The Doctor passes Jackie off as an aged-up Rose so the real Rose can sneak out of the TARDIS unnoticed. When they get found out...
The Doctor: Please, when Torchwood comes to write my complete history, don't tell people I traveled through time and space with her mother.
The Doctor: I've got a reputation to uphold.
- Mundane Utility: Jackie remarks that some of the technology Torchwood has developed would be great for carrying her shopping home.
- Never Heard That One Before: Yvonne, when the Doctor says Torchwood will never get inside the TARDIS, just smiles and retorts "et cetera".
- No, Except Yes:
Yvonne: They're invading the whole planet.
The Doctor: It's not an invasion, it's too late for that. It's a victory.
- No Sell: Rose discovers that the agents of Torchwood have enough psychic training to resist the Doctor's psychic paper.
- Oh, Crap:
- Played for laughs when the Doctor realizes Jackie is still on-board.
- Played straight when he realizes the Cybermen didn't make the Void Ship, and when Rose and Mickey find out who's inside.
- Also Rose after the psychic paper No Sell above.
- Sinister Geometry: The Void Ship, a seamless sphere with no detectable radiation or atomic mass until the Cybermen 'wake it up'. "It upsets people because it gives off — nothing. It is absent."
- Smash Cut: There's a warning on TV, telling people to stay in their homes for safety. Cut to a group of Cybermen effortlessly breaking into a family's home to attack.
- Uncommon Time: The music playing as the "ghosts" shimmer into Cybermen is in 5/4.
- Unreliable Narrator: Rose tells us this is "the story of how she died" while she is obviously still alive. She was probably referring to the fact that she was declared dead in her original universe after the events of this two-parter.
- Void Between the Worlds: The Doctor describes the Void as a completely alien realm where time, space and physical direction have no meaning we'd understand. "Some people call it Hell."
- Wham Line: "The sphere is not ours." Even better, as soon as the Cyberman says this, the Dalek theme starts playing.