The Doctor naively believes that his arch-nemesis, the Master, is safely out of the way... but the Master is due to return. With reinforcements...

Flung into a worm-hole by the Doctor and two of his future selves, the Master's days seem to be numbered, were it not for a passing scout-ship that intercepts the flailing vortex tunnel that imprisons him.

After being rescued from imminent death, the Master's good-fortune seems limitless on finding that his saviours are none other than his long-term allies... the Daleks.

And thus begins a sequence of events that will test the Doctor to his limits and beyond, as he is forced to fight against an alliance of his two most dangerous adversaries; confronting the Master, whose craving for power has led him to hatch this final, diabolical scheme... to destory the Doctor once and for all.