SixSeries Episode Number: 185
World Premiere: Sat 16 Dec 1967 - 5:24pm GMT [BBC One] (United Kingdom)
Running Time: 23 minutes 58 seconds
7.50 Million (UK)Appreciation Index: 51 (UK)
Chart Position: 59 () (UK)
Recorded on Sat 25 Nov 1967 in Lime Grove D
Archive State: 16mm t/r
The Ice Warriors invade the human's base, and it is up to the Doctor to repel them. Using the ioniser is the only way to defeat the Martians, but to do so could have consequences.