Perivale, England, the late 1980s. People are vanishing into thin air under the baleful stare of a very strange cat. The Doctor and Ace learn that, in the battle for survival, success can carry a terrible price...

The Doctor and Paterson manage to escape from the Master and join up with Ace and her friends, where the Doctor tries to find a way to get them all off the planet before it explodes.

Ace manages to transport the Doctor and the others back to Perivale but the Master is also there, preparing for a final showdown with the Doctor.