The Ministry of Time

As the conspiracy around the Ministry unravels, the narrator and Graham Gore have become lovers while hiding in a safe house from two rogue spies out of the future, the Brigadier and Salese. The threat escalates: fellow expat Arthur is killed, and Maggie's safe house is attacked, though she survives. The narrator, Maggie, Cardingham, and Gore flee to a prearranged refuge, where the narrator removes the tracking microchips from the expats' bodies — a revelation that leaves Gore feeling betrayed by her.

Seeking help, the narrator and her handler Adela are ambushed by the future spies. Adela kills Salese, but the Brigadier escapes. Adela then reveals the novel's central twist: she is the narrator's own future self, sent back from a timeline in which she and Gore married and had a son. In that timeline the Ministry murdered Arthur and Maggie, and Adela — having killed the mole Quentin in her own past — now feels betrayed by the Ministry's brutality and gives the narrator the access codes needed to fight back. Gore holds Adela at gunpoint while the narrator races to Ministry headquarters.

There she finds Simellia, her friend and fellow bridge, together with the Brigadier. Simellia is unmasked as the actual mole, motivated by her conviction that the future Ministry will curdle into a fascist regime complicit in climate catastrophe and renewed imperial violence. In the ensuing struggle the narrator damages the time door itself, which kills the Brigadier — and, unbeknowns to her at first, also kills Adela, since the door's destruction erases the timeline from which she came. Simellia escapes into hiding.

When the narrator returns home, Gore holds her at gunpoint too, forcing her to use Adela's codes to delete the Ministry's records before fleeing with the surviving expats. The narrator is subsequently fired, paid off, and permanently barred from the Ministry; in a closing conversation with the Secretary she learns that Simellia has been officially blamed for the time-door sabotage, and that Cardingham has been recaptured while Gore and Maggie remain missing. Months later she receives a photograph from Gore and Maggie showing they have made their way to Alaska, and she decides to go find them. In a final framing device, the narrator admits she has been writing the whole account as a letter to her own past self, to be read if the time door is ever rebuilt — closing with a postscript warning the reader not to repeat her mistakes, and assuring her that she is forgiven.