The first Doctor becomes the second in this exclusive recording of Doctor Who's original regeneration story, starring Patrick Troughton with narration by Anneke Wills.

Before the astonished eyes of his companions Ben and Polly, the Doctor's whole body has apparently been transformed . Now they are confronted by a stranger who claims to be their old friend - but how can they know whether to trust him?

Anneke Wills, who played Polly in the story, narrates this debut story for the second Doctor, first broadcast in 1966 and long since missing from the television archives.