On screen
Cast
44 credited performers
Dana Andrews
Dr. John Holden
Peggy Cummins
Joanna Harrington
Niall MacGinnis
Dr. Julian Karswell
Maurice Denham
Professor Henry Harrington
Athene Seyler
Mrs. Karswell
Liam Redmond
Professor Mark O'Brien
Reginald Beckwith
Mr. Meek
Ewan Roberts
Lloyd Williamson
Peter Elliott
Professor K.T. Kumar
Rosamund Greenwood
Mrs. Meek
Brian Wilde
Rand Hobart
Richard Leech
Inspector Mottrarn
Lloyd Lamble
Detective Simmons
Peter Hobbes
Superintendent
Charles Lloyd Pack
Chemist
John Salew
Librarian
Janet Barrow
Mrs. Hobart
Percy Herbert
Farmer
Lynn Tracy
Air Hostess
John Harvey
Hobart's Brother
Alan Beaton
Character not listed
Hyma Beckley
Character not listed
Ballard Berkeley
Character not listed
Ernest Blyth
Character not listed
Wallace Bosco
Character not listed
Daniel Brown
Character not listed
Jimmy Cains
Character not listed
George Curtis
Character not listed
Richard Duke
Character not listed
Shay Gorman
Character not listed
Laurence Hepworth
Character not listed
Walter Horsbrugh
Character not listed
Arthur Howell
Character not listed
Anthony John
Character not listed
Dan Lester
Character not listed
Leonard Llewellyn
Character not listed
Michael Peake
Character not listed
Paul Phillips
Character not listed
Anthony Richmond
Character not listed
Peggy Scott Sanders
Character not listed
Terry Sartain
Character not listed
Leonard Sharp
Character not listed
Bert Simms
Character not listed
Robert Brooks Turner
Character not listed