London, 1963: The Doctor returns to the place where it all began — alongside his latest companion, Ace, with unfinished business. Not for the first time, unusual events are unfolding at Coal Hill School. At 76 Totter's Lane, the Doctor discovers that his oldest foes — the Daleks — are on the trail of stolen Time Lord technology that he left on Earth long ago. The Daleks are planning to perfect their own time-travel capability, in order to unleash themselves across the whole of time and space.