The final segment of the Key to Time is at the heart of a devastating war between neighbouring planets Atrios and Zeos. The Fourth Doctor discovers that a sinister entity is manipulating events and the cost of obtaining the final segment may be more personal than he imagined.

Action, Adventure, Drama, Science Fiction, TV Movie

Tom Baker, Mary Tamm, John Leeson, John Woodvine, Lalla Ward, Davyd Harries