The Master uses The Rani's mind-controlling parasites to keep a meeting of Earth's leading scientists from being cancelled, and helps her plant transformation land mines for The Doctor, as he continues to propose an alliance with her in ruling over Earth.
Quest roles:
Anthony Ainley(The Master / Sir Gilles Estram), Peter Childs(Jack Ward), Terence Alexander(Lord Ravensworth), Kate O'Mara(The Rani)