Following the recent encounter with the Dæmons, the Doctor is called by Conran to visit the Master in his cell at Aylesbury Grange, UNIT's special detention centre. The Master tries to persuade the Doctor he has reformed, but it is a ploy. The Master escapes his cell using a simple ionic image controlled hologram. The Master believes he has escaped, but runs into the Doctor and UNIT, who are waiting for him. The Doctor has his own ionic image controller. Overmatched again, the Master is returned to his cell.
This dialogue heavy story sees Roger Delgado's Master trying to convince the Doctor that his (very short) imprisonment has changed him and that he's ready to change his ways, a theme that was to recur throughout the Master and Doctor's encounters.
According to one account, the Master had the appearance of Roger Delgado while on Gallifrey. According to another, he had Anthony Ainley's likeness. According to another one, the one with James Dreyfus's appearance was the incarnation who ran away from Gallifrey.
While fighting to extend his life at the end of his regeneration cycle, many bodies were possessed by the Beevers incarnation, but all kept somehow reverting to his real being until he finally regenerated into the MacQueen one. Hence, these sections cannot be strictly chronological
