The Doctor must unravel the real purpose of the recreation generator.

The Doctor and Romana are enjoying a holiday in Paris, 1979, when they become aware of a fracture in time. During a visit to the Louvre to see da Vinci's Mona Lisa, the Doctor purloins from a stranger, Countess Scarlioni, a bracelet that is actually an alien scanner device.

The tracer detects the second segment on the planet Calufrax. The TARDIS makes a bumpy landing, and the Doctor and Romana soon discover that they are not on Calufrax at all. They are in fact on Zanak, a planet that has been hollowed out and fitted with engines so that it can transmat through space and materialise around others - such as Calufrax - to plunder their mineral wealth, leaving them as shrunken husks held by gravitational forces in a "trophy room".

After returning to Gallifrey to claim his position as president, the Doctor strangely appears to turn traitor.

The Doctor orders Leela expelled to the wastes of outer Gallifrey.

In a South Yorkshire city, Ryan Sinclair, Yasmin Khan, and Graham O'Brien are about to have their lives changed forever as a mysterious woman, unable to remember her own name, falls from the night sky.

The Doctor tries to avert war.