The one where Ace comes back.
The TARDIS returns to Benny's home era, the 26th century, where she and the Doctor find themselves on the planet Arcadia — a pre-industrial paradise where most of the population is illiterate and nobody lives much past the age of 30.
Meanwhile Ace, after three years fighting in the Second Dalek War, has joined a group of irregular auxiliaries under the command of an Earth secret agent on an off the books mission to investigate the Spinward Corporation, the Mega-Corp that owns Arcadia.
This novel contains examples of:
- Arcadia: Invoked deliberately by the Spinward Corporation, which designed the planet Arcadia to be an Arcadian paradise.
- Attack! Attack! Attack!: Abslom Daak only knows one combat tactic — charge.
- Boisterous Bruiser: Abslom Daak only cares about two things — sex and violence — and he's extremely straightforward in his approach to both. While not even slightly attracted to him, Ace reflects that his attitude is rather refreshing when compared to most other men.
- Boom, Headshot!: How Ace kills Daak. By accident.
- Chainsaw Good: Abslom Daak carries a chainsword, and reacts to every combat situation by attempting to get close enough to use it.
- Cybernetics Eat Your Soul: Lacuna's connection to Pool may have turned her into a sadistic sociopath. Or she may have already been a sociopath — the text is unclear.
- Demolitions Expert: Ace always had shades of this, but as part of her level in badass she now supplements her homemade explosives with a lot of grenades. And smart missiles.
- Expendable Clone: Daak, as far as both Defries and the Doctor are concerned. Ace doesn't share this attitude — initially because she doesn't realise he's a clone (and his original's Heroic Sacrifice is a part of history that she wants to preserve), and eventually because she's grown to quite like the big idiot.
- Full-Frontal Assault: Used by Ace to help her steal another soldier's identity.
- Go Mad from the Isolation: Pool's vast intellect and multiple intelligences have only one channel of sensory input, through their connection to the human Lacuna. It's eventually revealed that many of Pool's minds have gone completely insane as a result of their long-term sensory deprivation.
- Human Resources: When people die on Arcadia, the Humble Counsellors steal their brain matter to add to Pool.
- Ignorance Is Bliss: The Doctor notes that the Arcadians are kept compliant by a combination of a lack of education and very short lifespans.The Doctor: "Long life and literacy! The first and second means by which knowledge is transmitted. And your masters have robbed these people of both! Youve created a society with no history, no culture. You can impose any laws and traditions you care to invent."
- Karma Houdini: Lacuna faces no punishment for her many crimes — including helping Pool exploit the people of Arcadia, torturing Britta, and killing Bertrand.
- Love Confession: A rare example in which it's an outright lie. Ace tells Daak she loves him to stop him from making a suicide attack — but it's actually because she believes his survival is essential to maintaining the integrity of the timeline, and his only two interests seem to be dying in a spectacular fashion and getting into her pants.
- The Maze: Thanks to Pool's reality warping, the space station orbiting Arcadia has become all but impossible to navigate. The Doctor and his friends spend hours travelling, only to end up where they started.
- Mecha-Mooks: The Humble Counsellors are actually Pool's android servants.
- Mind Hive: Pool is this writ large, with a gigantic space station as its body and dozens of consciousnesses still active within its vast brain.
- My Brain Is Big: Lacuna's head is noted to be unnaturally large, possibly as a result of the cybernetics needed to connect her to Pool.
- One Nation Under Copyright: Pretty much all of the human colonies have become this by the 26th century — but the book's appendix notes that the long-term economic effects of the Dalek War resulted in the fall of the corporations and the return of more traditional forms of government.
- People Farms: The population of the planet Arcadia is maintained solely so that Pool can harvest their brains.
- Powered by a Forsaken Child: Benny is very concerned that, in his fascination with Pool's super-intelligence, the Doctor appears to have lost sight of the fact that it was made by killing thousands of people and stealing their brain matter.
- Reality Warper: Pool's intelligence has become so advanced that it's capable of Block Transfer Computations, the advanced mathematics that lets you create and reshape matter.
- Rogue Agent: Isabelle Defries is operating off the books, because the Spinward Corporation has enough influence over the government to get any investigation into them shut down. Her superior is fully aware of what she's doing, but has to officially deny any knowledge of her operation.
- Sadist: Lacuna, and through her Pool, gain their primary entertainment and stimulation by torturing and degrading Britta Hoffman.
- Sinister Shades: Worn by Ace, and noted to add to her general air of grimness.
- Took a Level in Badass: Ace has never been a shrinking violet (remember, this is the girl whose Dalek-killing exploits inspired the Moment of Awesome trope), but this book upgrades her to a heavily armed veteran soldier with an arsenal of guns and explosives and a shoot first attitude.
- Town with a Dark Secret: The people of Arcadia live lives of luxury, on a planet where everyone is young and beautiful and the weather is always perfect. They all die well before they reach 40, and the Humble Counsellors harvest their brains for Pool.
- Tracking Chip: Standard issue in the military, embedded in each soldier's chest. Ace uses a knife and some plastigraft to perform some light identity theft.
- What Happened to the Mouse?: When Britta arrives on the station, she mentions there being a large staff of ordinary corporate drones. After Lacuna brings her into Pool's inner sanctum, the staff are never mentioned again — even when the station is destroyed. It's mentioned that at least some parts of the station can be sealed off and can survive atmospheric entry — but no attempt is made to warn all these people. Plus, a short time before, the Humble Counsellors had told everyone living on the surface of Arcadia that any offworlders they see will be infected with horrible plagues, and should be killed on sight...