The owner of a coal mining operation, falsely imprisoned for fratricide, takes a drug to make him invisible, despite its side effect: gradual madness.
Cedric Hardwicke
as Richard Cobb
Vincent Price
as Geoffrey Radcliffe
Nan Grey
as Helen Manson
John Sutton
as Dr. Frank Griffin
Cecil Kellaway
as Inspector Sampson
Alan Napier
as Willie Spears
Forrester Harvey
as Ben Jenkins
Ernie Adams
as Minor Role (uncredited)
Jimmy Aubrey
as Plainclothesman (uncredited)
Walter Bacon
as Fight Spectator (uncredited)
Billy Bevan
as Jim (uncredited)
Clara Blore
as Woman (uncredited)
