The Ark is the sixth serial of the third season of the British science fiction television series Doctor Who, which was first broadcast in four weekly parts from 5 to 26 March 1966.
The inhabitants of the Ark discover that they have uninvited guests.
The Ark (Doctor Who)
The third season of British science fiction television series Doctor Who began on 11 September 1965 with the story Galaxy 4 and ended on 16 July 1966 with The War Machines. Only 17 out of 45 episodes survive in the BBC archives; 28 remain missing. As a result, only three serials are complete.
Cover art of the Region 2 DVD release for first serial of the season