Part FourSeries Episode Number: 425
World Premiere: Sat 21 Feb 1976 - 5:46pm GMT [BBC One] (United Kingdom)
First Broadcast: Wed 30 Apr 1980 - 5:30pm CDT [WTTW 11 Chicago]
Running Time: 24 minutes 46 seconds
11.10 Million (UK)
Chart Position: 23 () (UK)
Recorded on Tue 02 Dec 1975 in TC4
Keeler has been infected by the alien pod and is transforming into a Krynoid. Chase refuses to listen to the Doctor's warning and throws him into a compost machine.