Following his regeneration into a younger body, after his first encounter with the cybermen, The Doctor, Ben and Polly discover human scientists in a colony on the planet Vulcan attempting to reactivate three powered-down Daleks. The scientists don't listen to The Doctor's warnings that the Daleks are dangerous, and then the Daleks begin to secretly reproduce themselves, in order to seize control of the colony...
Although all six episodes of this serial have been lost, there exists an animated adventure that uses surviving audio from the BBC vaults to reconstruct the story.
