STORY PLOTLINE
The TARDIS arrives in December 1986 at a South Pole Space Tracking station where the personnel, under the command of General Cutler, are engaged in trying to talk down a manned space capsule that has got into difficulty.
The Doctor realises that the problem stems from the gravitational pull of another planet that has entered the solar system and is now heading for Earth. His words are borne out when the base is invaded by a force of alien Cybermen
