"A fact-based story about a man who posed as an American Communist for years as part of a secret plan to infiltrate their organization."
Frank Lovejoy
as Matt Cvetic
Dorothy Hart
as Eve Merrick
Philip Carey
as Mason
James Millican
as Jim Blandon
Richard Webb
as Ken Crowley
Konstantin Shayne
as Gerhardt Eisler
Paul Picerni
as Joe Cvetic
Roy Roberts
as Father Novac
Edward Norris
as Harmon
Ron Hagerthy
as Dick Cvetic
Hugh Sanders
as Clyde Garson
Hope Kramer
as Ruth Cvetic
Lyle Latell
as FBI Officer Cahill
Edwin B. DuPar
Director of Photography
Gordon Douglas
Director
Crane Wilbur
Screenplay
Folmar Blangsted
Editor
Bryan Foy
Producer
Max Steiner
Original Music Composer
Jean Baker
Script Supervisor
Leo K. Kuter
Art Direction
Lyle B. Reifsnider
Set Decoration
Gordon Bau
Makeup Artist
Leslie G. Hewitt
Sound
Oren Haglund
Assistant Director