The TARDIS arrives on an apparently deserted and deactivated space station Nerva, otherwise known as the Ark, orbiting Earth in the far future. There the Doctor, Sarah and Harry discover the last survivors of the human r…

The Doctor, Sarah and Harry arrive on a desolate and apparently deserted Earth to discover that a group of shipwrecked astronauts from a human colony, GalSec, have been lured there by a fake distress call. One of their n…