Characters played by Dennis O'Keefe
Joe Dennison
Characters played by Margaret Sheridan
Marline Miller
Characters played by Philip Friend
Inspector Hector 'Mac' McClaren
Characters played by Alan Wheatley
Thompson Blake
Characters played by Francis De Wolff
Yeo
Characters played by Eric Berry
Hunziger
Characters played by Gudrun Ure
Sgt. Smith (as Ann Gudrun)
Characters played by Paul Hardtmuth
Dr. Eric Miller
Characters played by Colin Tapley
Sir Stafford Beach
Characters played by Donald Gray
Commander Gilles
Characters played by Cyril Chamberlain
Castle
Characters played by Michael Balfour
Hoxie
Characters played by Seymour Green
Lascelles