Emancipation of the Daleks
Bill Potts has an unexpected visitor: another Bill Potts from twenty years in the future. Bill summons The Doctor, who confirms that the other Bill is the genuine article. She has come to see her younger self for a reason… but she can’t say what it is without creating a paradox!
Moments later, the TARDIS Cloister Bell sounds. A damaged Dalek war saucer is travelling back through the time vortex on a collision course. The Doctor dematerialises the TARDIS to avoid it, only to cause the spaceship to crash-land in Earth’s recent past. When it re-materialises, the TARDIS is now in a world altered beyond recognition. The city of Bristol has been reduced to rubble, save for an interstellar rocket construction site and a top-security research complex. The complex is guarded by ‘Robomen’ and flying security drones piloted by Dalek mutants.
He couldn’t be more wrong. And Bill is about to discover that her past, present and future are no longer her own.
Based on Dalek technology, researchers at this top-secret facility developed “ever-lasting batteries”, drones, special tanks, laser guns and warp drives.
Bill previously encountered the Daleks in The Pilot.
The Doctor tells Bill that the TARDIS has a yearometer. (“The Cave of Skulls“; Doctor Who in an Exciting Adventure with the Daleks, Byzantium!, Eater of Wasps; The Doctor Strikes Back)
The Doctor has had past dealings with the Robomen, and explains that the process usually can’t be reversed. Without the Daleks‘ control, they usually go insane and commit suicide. (The Dalek Invasion of Earth)