THE DEATH ZONE, A CONCEALED AND FORBIDDEN region of Gallifrey, has remained inert for millennia. However, it has now been re-activated and is responsible for draining a critical amount of energy from the Eye of Harmony.
Having unsuccessfully transmatted two members of the High Council into the area to investigate, the Time Lords discover that their consequent option, the Doctor, has been all but removed from time. Furthermore, the traces of his personal time streams converge on the Death Zone. It becomes apparent that ancient Time Lord technology is being used to lift each of the Doctor’s incarnations and a number of his companions from their time streams in an effort to transport them to the Death Zone. Facing a crisis, the High Council coerces the Master into locating and rescuing the Doctor.