Barbara Wright and Ian Chesterton, two humble teachers during 1963, discover a genius student's grandfather, simply known as "the Doctor", and his police box time machine. Deciding that the pair knows too much about his otherworldly origins, they are whisked away on a journey through time and space.

William Hartnell
as Dr. Who

William Russell
as Ian Chesterton

Jacqueline Hill
as Barbara Wright

Carole Ann Ford
as Susan Foreman

Derek Newark
as Za

Alethea Charlton
as Hur

Eileen Way
as Old Mother

Jeremy Young
as Kal

Howard Lang
as Horg

Reg Cranfield
as Policeman (uncredited)