It begins with Ian Chesterton's surreal nightmare involving familiar foes. Afterwards Ian, the First Doctor, Barbara and Vicki battle unfamiliar creatures on an icy planet. Meanwhile the Seventh Doctor and Ace arrive in a rural village on 1950s Earth. Terrible things start happening and Ace is worried by the Doctor's obvious anguish. Is he in some way responsible for it all?

Ian Chesterton has a surreal nightmare involving familiar foes. Then the First Doctor and his companions face a waking nightmare with unfamiliar creatures on a frozen world. Meanwhile the Seventh Doctor and Ace arrive on 1950s Earth, where the ruryl idyll of a village is soon shattered. What is the cause of the Seventh Doctor's anguish? Perhaps it is events from his past?