Guest Stars Julian Glover as Barton Barrie Ingham as Dr. John Thorndyke Michael Harding as Ticket Collector Derek Smith as Professor Popplebaum Peter Sallis as Dr. Jervis George Innes as Adolph Schonberg Graham Seed as Porter Keith Taylor as Fierce Little Man Nicholas Selby as Superintendent Miller Max Faulkner as Mounted Policeman Eric McCaine as Inspector Badger Peter Beton as Mr. James (Reporter) Clive Rogers as Victim