Episode Detail: The Two Doctors - Doctor Who
"The Two Doctors," Part 1 of two. Two incarnations of the Time Lord (Colin Baker, Patrick Troughton) join to stop Dastari and Chessene from performing dangerous experiments in time. Dastari: Laurence Payne. Chessene: Jacqueline Pearce. Peri: Nicola Bryant. Jamie: Frazer Hines.