Strange forces are draining the energy from the Time Lords home planet of Gallifrey. Desperate for a solution, the Time Lords collect the three regenerations of the Doctor from their respective timelines and set them on the problem of tracing the losses.Episode 1In search of the Doctor, an antimatter creature attacks UNIT and theDoctor is forced to send an SOS to his people, the Time Lords, but theyhave troubles of their own.Episode 2Following the advice of the First Doctor, the Third Doctor and Jo havecrossed through the black hole to the strange, desolate world ofantimatter.Episode 3The Doctors are trapped in the universe of antimatter. There theyconfront the creator of the world – Omega, a legendary figure fromTime Lord history, long believed dead.Episode 4Omega intends to escape his antimatter world and needs the Doctorsto take his place. But the Doctors discover the terrible truth aboutOmega and realise that he can never escape.