Episode 5Series Episode Number: 208
World Premiere: Sat 25 May 1968 - 5:16pm BST [BBC One] (United Kingdom)
Running Time: 21 minutes 55 seconds
6.80 Million (UK)Appreciation Index: 57 (UK)
Chart Position: 44 () (UK)
Recorded on Fri 03 May 1968 in Riverside 1
Archive State: Missing
The Cybermen reveal their plans to invade Earth, using the Wheel as a guiding beacon. The Doctor sends Jamie and Zoe on a dangerous spacewalk to the Silver Carrier.