Dorothy McGuire as Helen

George Brent as Professor Warren

Ethel Barrymore as Mrs. Warren

Kent Smith as Dr. Parry

Rhonda Fleming as Blanche

Gordon Oliver as Steve Warren

Elsa Lanchester as Mrs. Oates

Sara Allgood as Nurse Barker

Rhys Williams as Mr. Oates

James Bell as Constable

Erville Alderson as Dr. Harvey (uncredited)

Ellen Corby as Neighbour (uncredited)

Myrna Dell as Murder Victim (uncredited)

George Holmes as The Killer's 'Shadow' (uncredited)

Stanley Price as Starry-eyed Man (uncredited)

Robert Siodmak as The Killer's 'Eye' (uncredited)

Richard Tyler as Freddy (uncredited)

Charles Wagenheim as Desk Clerk (uncredited)

Larry Wheat as Minister (uncredited)