Noel Willman

as Bruno Merk

as Mr Justice Bates

as Father Nassau

as Franz Bayer

as Holvera (1 episode)

as Sir Walter Sloane (1 episode)

as Theopolos (1 episode)

as Sir Hugh Anderson (1 episode), as Sir Hugh Alexander (1 episode)

as Magistrate (1 episode)

as Aramis (9 episodes)

as Za-Tor

as Dr. Franklyn

as Razin, Liberius' Lieutenant

as Dr. Ravna

as Webster

as Johnson

as Prison Governor

as Colonel Rodriguez (1 episode)

as Inspector Thomas

as Nigel Pickering

as The Lawyer

as Interrogator

as Chief of Police

as Aubrey Clark

as Dr. Clifford Preston (1 episode)