Part FourSeries Episode Number: 417
World Premiere: Sat 13 Dec 1975 - 5:56pm GMT [BBC One] (United Kingdom)
First Broadcast: Wed 16 Apr 1980 - 5:30pm CST [WTTW 11 Chicago]
Running Time: 24 minutes 30 seconds
11.40 Million (UK)
Chart Position: 15 () (UK)
Recorded on Sat 26 Jul 1975 in TC8
The Doctor and Sarah are desperate to warn UNIT of the alien invasion, but nobody will believe them. The Kraals' release their android duplicates, including one of the Doctor.