The Mysterious Doctor

John Loder

Sir Henry Leland

Eleanor Parker

Letty Carstairs

Bruce Lester

Lt. Christopher 'Kit' Hilton

Lester Matthews

Dr. Frederick Holmes

Forrester Harvey

Hugh Penhryn

Matt Willis

Bart Redmond

Phyllis Barry

Ruby

David Clyde

Tom Andrews

Clyde Cook

Herbert

Art Foster

Saul Bevans

Creighton Hale

Luke

Hank Mann

Roger Porley

Harold De Becker

Peddler

Stuart Holmes

Civil Defense Officer

Crauford Kent

Army Commander