The Doctor is sent on another mission for the Time Lords, this time to deliver a strange looking message pod that will only open for the right person. Trouble is, they’ve neglected to tell him who it’s for. The TARDIS whisks them away to Skybase One, a space station above a desolate planet called Solos.
The natives are about to get their wish for independence from the Great and Bountiful Human Empire, but Skybase’s commander has other ideas. Meanwhile, the natives have begun to mutate into insectoid monsters, and it’s up to the Doctor and Jo to discover the source of the plague on this episode of Lonely Gods.