Episode 4
Series Episode Number: 152World Premiere: Sat 4 Mar 1967 - 5:51pm GMT [BBC One] (United Kingdom)
Running Time: 23 minutes 28 seconds
8.10 Million (UK)
Appreciation Index: 58 (UK)Chart Position: 44 () (UK)
Recorded on Sat 25 Feb 1967 in Lime Grove D
Archive State: 16mm t/r
The moonbase is cut off from Earth and under siege. The Cybermen launch an all-out attack and the Doctor formulates a dangerous plan to repel the invaders.