Guest Stars Douglas Wilmer as Prof. Van Dusen Mark Eden as Roderick Varley Margaret John as Receptionist William Moore as Station Sergeant Charles Morgan as Mallory Robert Hartley as Police Doctor Wallas Eaton as Sterling Dennis Chinnery as Morey Michael Guest as Policeman Laurence Payne as Prescott Veronica Strong as Miss Rossmore / Mrs. Morey William Mervyn as Sir Hector Drummond, Bt.
