As the Doctor obeys a mysterious summons to Gallifrey, he has visions of the assassination of the Lord President. The Doctor enters the Panopticon wearing borrowed robes, but when the President dies the Doctor is caught with staser rifle in hand. Chancellor Goth is anxious to see the Doctor executed before Goth's likely election to the presidency, and speeds up the Doctor's trial over Cardinal Borusa's objections. To gain his freedom, the Doctor announces his candidacy for the office of Lord President and investigates with Castellan Spandrell. When they find a technician's compressed body, the Doctor knows who has been framing him: the Master! The Doctor connects his living mind to the Matrix, where a battle ensues between the Doctor and the Master's accomplice, Chancellor Goth. The Master is using Goth to gain a far greater prize than the presidency, control of Rassilon's Eye of Harmony.