Part OneSeries Episode Number: 382
World Premiere: Sat 28 Dec 1974 - 5:35pm GMT [BBC One] (United Kingdom)
First Broadcast: Tue 26 Feb 1980 - 5:30pm CST [WTTW 11 Chicago]
Running Time: 24 minutes 11 seconds
10.80 Million (UK)Appreciation Index: 53 (UK)
Chart Position: 25 () (UK)
Recorded on Tue 21 May 1974 in TC3
UNIT are called in when top secret plans and valuable equipment is stolen from high security establishments. The newly regenerated Doctor suggests that the thief may not be human.