"This is High Treason, and for this you deserve death. However, in view of your past service, the sentence is commuted to exile. You leave Gallifrey this day, never to return." A chain of events has been set in motion that will change the Fifth Doctor and Peri forever. A chain that involves old enemies as well as old friends. The answers lie in the origins of a conflict that will affect the whole cosmos — a conflict that will find humans, Sontarans, Draconians and even Cybermen fighting together for the greater good and glory. For the Supremo.