Episode EightSeries Episode Number: 227
World Premiere: Sat 21 Dec 1968 - 5:15pm BST [BBC One] (United Kingdom)
Running Time: 25 minutes 3 seconds
7.00 Million (UK)Appreciation Index: 53 (UK)
Chart Position: 80 () (UK)
Recorded on Fri 08 Nov 1968 in Lime Grove D
Archive State: 16mm t/r
The Cybermen have launched their deadly megatron bomb which will destroy all life on Earth unless the Doctor can deactivate the homing signal.