In his fourth incarnation, the Doctor landed on the planet Zeta Minor, a world located on the edge of the known universe, the bridge-point for the opposite universes of matter and anti-matter. Now in his fifth life, the Doctor meets the same race the landed there before, and once again they are eager to harness its secrets—with terrifyingly dangerous results. Caught up in a situation akin to a Jacobean revenge tragedy, the Doctor must fight his way through layers of court intrigue before he can try to stop the people really in control from allowing the forces of Anti-matter free reign to destroy every life-form in the universe.