Episode Four
Series Episode Number: 307World Premiere: Sat 22 Jan 1972 - 5:51pm GMT [BBC One] (United Kingdom)
First Broadcast: Fri 10 Oct 1975 - 6:30pm CDT [WTTW 11 Chicago]
Running Time: 24 minutes 17 seconds
9.10 Million (UK)
Chart Position: 40 () (UK)
Recorded on Tue 19 Oct 1971 in TC8
Archive State: PAL 2 VT
The Controller betrays the Daleks and is exterminated. The Daleks travel back in time to the 20th Century to ensure that the peace conference fails.