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.
In search of the Doctor, an antimatter creature attacks UNIT and the
Doctor is forced to send an SOS to his people, the Time Lords, but they
have troubles of their own.
Following the advice of the First Doctor, the Third Doctor and Jo have
crossed through the black hole to the strange, desolate world of
The Doctors are trapped in the universe of antimatter. There they
confront the creator of the world – Omega, a legendary figure from
Time Lord history, long believed dead.
Omega intends to escape his antimatter world and needs the Doctors
to take his place. But the Doctors discover the terrible truth about
Omega and realise that he can never escape.