Following the recent encounter with the Dæmons, the Doctor is called by Conran to visit 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.