This episode marks the end of the Divergent Universe arc, as well as the end of the Zagreus arc. Released in December of 2004, it was also the very last episode in which Paul McGann was the incumbent Doctor — between this and his next episode, the series would return and introduce Christopher Eccleston his successor.
One day, the Eighth Doctor is stranded on a little blue planetoid in space, made of water and inhabited by savages. The TARDIS is nowhere to be found.
Charley and C'rizz were taken away from him by Rassilon and hooked up to dream machines. With the help of the Kro'ka, who has been working for him all along, Rassilon makes them re-live their worst nightmares. For Charley, it's the guilt of having deprived Simon of his income on the R101, the Survivor Guilt over watching Rathbone die, and the pain at the realisation that she can never see her mother again. She's smart enough to know that it's all fake, though, especially once Simon starts referencing Peter Davison's character from her previous dreamscapes. She tells the Kro'ka to release her from the dream.
C'rizz isn't quite so strong, and his dream of being reunited with L'da and reliving the day of his wedding almost breaks him. It's revealed that his church, the Foundation, is a cult more than anything. And that it revolves around saving people by killing them. And that C'rizz was once a very, very adept assassin. He's lost that part of his identity now, because his race doesn't just change their skin color automatically — they also adjust their personality to whomever they live with. Slowly but steadily, C'rizz has become a perfect companion to the Doctor and Charley, at the cost of the previous personality that was imprinted on him.
When they wake up (with C'rizz very shaken by the experience), Rassilon tells them both that the Doctor has been keeping a secret from them. Zagreus isn't inside the Doctor anymore. And without Zagreus lingering inside his mind, the Doctor is now free to go home, and Rassilon isn't at all sure that Charley and C'rizz would be welcome on that journey. Charley tells Rassilon to stuff it, and they enter the blue planetoid to go look for the Doctor.
The Doctor, meanwhile, meets three people on the planetoid: Guidance, the leader of the Foundation cult; Keep, an inexplicably French Great White Hunter; and Keep's wife, Perfection, who's played by Daphne freaking Ashbrook! Perfection is pretty tired of her idiotic husband, and decides to get the Doctor out of his shirt and into her bed instead. The Doctor's a bit confused, especially when a little savage girl is accidentally killed and he and Perfection find themselves hunted as the most dangerous game.
Charley meets Keep, who takes her out on said hunt, and she wonders why he speaks French and why nothing on the planetoid makes any kind of sense. C'rizz meets Guidance... his father. He has a proper Heroic BSoD when it's revealed that the island contains the Foundation itself. It's a simple little hole in the ground with a cover on it. The key to it is C'rizz' necklace. All his travels, Guidance says, all his adventures, were simply a way to guide him to the island as a vessel for the key. Nothing else mattered.
When Rassilon created the Divergent universe in a Möbius time loop, the blue planetoid started creating life, then destroying it once the cycle was at its end, then creating it anew. The Divergence started experiments to avoid the loop, but they never could break through it. Over and over again, the cycle of reincarnation would overwrite all life and all experience. Not just briefly, like in Light City, or for a single war, as seen in "The Last", but for the entire nine galaxies of the Divergent universe. When the Doctor entered the Divergent universe, the Divergence saw him as a way to break the cycle, and trapped him in Scherzo — and all subsequent experiments — to study him. From his data, they created the perfect creature: the woman named Perfection. But Perfection escaped and married Keep for his money, and Keep subsequently took control of the cult of the Foundation.
Keep turns out to be much more than he seems, as well. Specifically, he's the food from the very first experiment. He followed the Doctor and Charley out of Scherzo and into the rest of the planet, always changing, evolving, and eventually becoming a vessel for all of the Divergence. He's the entire Divergent race, plus the Doctor's consciousness, plus Charley's memories, all rolled into one. And he's angry.
"The Foundation" was a bit of a misnomer all along. It's not a "Foundation"... it's the Foundry of Rassilon. And when the planets align, when the end of the time cycle approaches, Rassilon can use it to escape from the Divergent universe. The entire cult of the Foundation was just a story to get Guidance to the Foundry with the key. Guidance was as much used as C'rizz was. C'rizz, meanwhile, is completely broken and just about ready to shoot the Doctor if it means he can re-live the cycle of his own life and meet L'da again.
And Perfection tells the Doctor that she'd love to repopulate the universe together with him. They could be fantastic together. Two perfect beings. "Adam and Eve." Her brains and his beauty. The Doctor, quite scared now, asks her to stop flirting and, more importantly, how she could possibly know about the story of Adam and Eve. Things start to make a little more sense when it turns out Rassilon was telling the truth. Zagreus left the Doctor's mind a long time ago. And Perfection committed suicide a long time ago, no longer able to bear the way that Keep abused her. The woman who claims to be Perfection is Zagreus.
Rassilon is more than a bit pleased with how everything is working out. Until Keep tells him that they've been through all this 83 times already. For 83 time cycles, each lasting years and years, Rassilon would start the cult of the Foundation, Guidance and some broken Foundation child would end up on the blue planetoid with the key, and everything would be reset at the end anyway because Failure Is the Only Option. Until now. Because this time, Keep and his Divergent consciousness have copied the mind of the Doctor into themselves. And they have a TARDIS. They can escape when the end of the cycle is reached, and Rassilon will be left in the newly reset universe, with his memories intact as punishment for his deeds.
Zagreus dives into the TARDIS and tries to pilot it to the main universe. She's a little bit surprised when she realises she's Failed a Spot Check: it's not the TARDIS at all, but Keep, who traps her inside himself. The actual TARDIS is standing a few feet away.
The Doctor sees this as an opportunity to escape the Divergent universe and start his life anew. But before he does, he needs Charley and C'rizz to make a pact with him. No jealousy, no drama, no yearnings (Charley blushes a bit). C'rizz needs to develop his own personality and repent for his FaceHeel Turn. Charley needs to stop her You Are Worth Hell attitude and accept that their friendship is more important than anything. With seconds to spare, they pilot the TARDIS out of the Divergent universe forever.
The world is reset. Rassilon and the Kro'ka find themselves trapped in Scherzo, surrounded by the piercing hellish screech and helplessly re-enacting the Doctor's and Charley's dialogue for all eternity. Zagreus and the Divergence consciousness of Keep decide to set aside their differences and start a little Adam and Eve Plot of their own. The Doctor, Charley and C'rizz open the TARDIS doors to find the good old universe waiting for them, as well as an entire army of Daleks and one very surprised Davros.
- Abhorrent Admirer: Perfection to the Doctor. She's pretty and all, but he's just not in the mood. Taken Up to Eleven when he realises she's Zagreus.
- Actor Allusion: Daphne Ashbrook once again plays a woman who wants to shag the Eighth Doctor. Eight briefly uses the word "grace" at the start of the episode as a nice little nod to the TV movie. They can't say grace at what's supposed to be the Doctor's last meal because "there's no grace here."
- Actor-Shared Background The Doctor has an excellent knowledge of Liverpool FC - Paul McGann is a lifelong Liverpool supporter.
- Adam and Eve Plot: What Keep apparently wants with Perfection, but she wants it with the Doctor, even mentioning the Trope Namer. Her mentioning this is one of the clues for the Doctor that something is odd about her.
- Alien Lunch: The Doctor is served a dish of jungle bugs. He loves it.
- And I Must Scream/Fate Worse than Death: Rassilon and the Kro'ka are cast into Scherzo, with all of their memories intact, and forced to act out the exact same dialogue that the Doctor and Charley went through. And with no Keep or Zagreus willing to check up on the experiment, it's entirely unclear what, if any, chance of escape they'll have.
- And the Adventure Continues:Charley: We're home then?
Daleks: You are the Doc-tor!
Davros: Ah, Doctor. Welcome back. I've... We've been waiting for you.
The Doctor: Yes, Charley, we're home.
- The Assimilator: Keep. He has absorbed everything from the dead Divergents, has absorbed various species, and plans to absorb the dominant species from every Universe.
- Arc Words: The end of the Divergent arc: revolution, reincarnation, evolution, death and rebirth, becoming food for other lifeforms, reptilian into mammalian, fluid consciousness between multiple beings, mother, spinning in a circle, breaking free of the cycle, the next life and the beyond.
- Artifact Title: The Doctor's "everlasting matches" only last for about 3 minutes, according to Charley.
- At Least I Admit It: As Rassilon says "Better an honest villain than a counterfeit hero." Charley gives him a Shut Up, Hannibal!.
- Brief Accent Imitation: Whilst eating some bugs with Perfection and Keep, the Doctor puts on a cockney accent for comedic effect for a couple lines. It's not much good.
- Call-Back: Large parts to the Creed of the Kromon, and to Storm Warning.
- Scherzo's events gets a mention later in the story. Kro'ka and Rassilon's dialogue as they're stuck in Scherzo mirror the Doctor's and Charley's nearly word for word.
- The Chessmaster: Rassilon.
- Clingy Jealous Girl: Charley in the last episode admits she is this.
- Continuity Nod: The Doctor mentions to Charley that they're just tourists.
- Dirty Coward: The Kro'ka.
- Dismantled MacGuffin: Two halves of a single amulet.
- Doom Magnet: The Doctor's tendency to get into trouble gets called out on.
- Driven to Suicide: Perfection, a long time ago. You probably would be too, if you were hitched to Keep.
- Egomaniac Hunter: Keep.
- Evil vs. Evil: By the end 3 sides. Rassilon, Keep and Zagreus.
- Evil Laugh: Rassilon gives one at the end of episode 5.
- Eureka Moment
- Femme Fatale: Perfection.
- A Form You Are Comfortable With
- Gambit Pileup
- Gender Bender: Zagreus.
- Giant Enemy Crab
- Gold Digger: Perfection will readily admit it.
- Grand Finale: For the entire plot since "Storm Warning".
- Gratuitous French: Daqar Keep. This is one of the clues to the Doctor that he is a composite character of him and Charley.
- "Groundhog Day" Loop: On a universal scale.
- Healing Factor: The Keep
- Hoist by His Own Petard: Rassilon gets caught in the time loop he installed in the Universe to trap the Divergence, which has already happened to him 84 times.
- Hunting the Most Dangerous Game
- I Never Told You My Name: Is how the Doctor finds out The Reveal.
- Lame Pun Reaction: The Doctor throws a few puns at us, for the first time since the Divergence Arc started. He starts regretting this when he sees the Giant Enemy Crab.The Doctor: Oh, come on Doctor, a bad pun for an epitaph?
- The Load: Kro'Ak reveals that this is how C'rizz thinks of himself.
- Lotus-Eater Machine
- C'rizz, I Am Your Father
- Mind Screwdriver
- The Missus and the Ex: Charley meeting Perfection has this vibe, because that's at least how Charley sees it.
- Multiversal Conqueror: What Daqar Keep aims to be.
- Pollard, Charley Pollard
- Necessary Evil: Rassilon alludes he himself is this when Charley says he's got Evil stamped through him.
- Never Smile at a Crocodile
- No, Mr. Bond, I Expect You to Dine
- Not So Different: The Keep is what Charley and the Doctor could have turned into if they hadn't undone their Fusion Dance in Scherzo.
- Off the Rails
- O.O.C. Is Serious Business: The Doctor seems at least a little bit receptive to Perfection's flirting, getting rather bashful and catching her innuendos and so on. Charley points out that based on her experience, he's not like that. It turns out that he realized she was just trying to manipulate him, suggesting that he only reacted like that to make her think she was succeeding.
- Out-Gambitted: The Divergence / The Keep are more clever than Rassilon. 84 times so far.
- Playing Both Sides: Rassilon.
- Pull the Thread: C'rizz does this to figure out where he is.
- Quicksand Sucks
- The Scottish Trope: The Doctor invokes the play again. As does Rassilon.
- Sealed Evil in a Can: Rassilon and Zagreus are trapped in the Divergent universe. Even at the end.
- She Is Not My Girlfriend: Said word-for-word by the Doctor.
- Ship Sinking: The Doctor very clearly tells Charley to stop yearning for him. It's fine that they love each other, but on a friendship level only.
- Shirtless Scene: Zagreus gets Eight out of his shirt with relative ease, when she checks him for leeches. She'd be quite happy to make him lose the rest of his clothes as well.
- Shout-Out: The Doctor tells Rassilon he's very discombobulated.
- This Banana is Armed: Charley threatens the Keep with a slingshot and some sweets. She causes him to blow his own foot off with his shotgun.
- Title Drop
- Unholy Matrimony: Keep and Zagreus, at the end.
- Unresolved Sexual Tension: Between the Doctor and Perfection. Subverted; she was Zagreus all along, trying to manipulate him with their newly acquired feminine wiles. And he knew it from almost the moment they met, so, assuming he's not the type to enjoy being propositioned by sapient anti-time viruses that pretty much only just got done possessing him, he was probably pretending to be into her so she wouldn't realize she'd been found out.
- Rassilon Had A Point
- Vitriolic Best Buds: Charley and C'rizz, when they're not genuinely at each other's throats. The Doctor is fed up with it in any case.
- The Watson / The Chick: Charley demonstrates how one is ought to go "Doctor! Doctor, what's HAPPENING Doctor!?"
- Weak-Willed: It's finally revealed why C'rizz never seemed to have much of a personality. His identity is as chameleonic as his skin. Completely Played for Drama.
- We Have Reserves: The Keep thinks this of the porters.
- Wicked Cultured: Rassilon quotes Shakespeare.
- Yandere: C'rizz seems to think this about Charley, since he accuses her of being a "bunny boiler", despite having only just learned what a bunny is in Caerdroia. Maybe he watched Fatal Attraction on the TARDIS some time.