Part Three
Series Episode Number: 408World Premiere: Sat 11 Oct 1975 - 6:07pm BST [BBC One] (United Kingdom)
First Broadcast: Thu 3 Apr 1980 - 5:30pm CST [WTTW 11 Chicago]
Running Time: 23 minutes 50 seconds
9.10 Million (UK)
Appreciation Index: 57 (UK)Chart Position: 29 () (UK)
Recorded on Mon 14 Jul 1975 in Television Centre 3
Lost in the universe of antimatter, the Doctor communes with the creature and makes a bargain. Sarah discovers Professor Sorensen's dark secret which threatens to overwhelm him.
Home Region: