Colin Baker Doctor Who Actor Nicola Bryant Peri Brown Actor Lynda Bellingham The Inquisitor Actor Michael Jayston The Valeyard Actor Tony Selby Sabalom Glitz Actor Joan Sims Queen Katryca Actor Glen Murphy Dibber Actor Tom Chadbon Merdeen Actor Roger Brierley Drathro Actor David Rodigan Broken Tooth Actor Adam Blackwood Balazar Actor Timothy Walker Grell Actor Billy McColl Humker Actor Sion Tudor Owen Tandrell Actor Robert Holmes Writer Nicholas Mallett Director John Nathan-Turner Producer Eric Saward Script Editor