A physician on death row for a mercy killing is allowed to experiment on a serum using a criminals' blood, but secretly tests it on himself. He gets a pardon, but finds out he's become a Jekyll-&-Hyde.
Boris Karloff
Evelyn Keyes
Bruce Bennett
Don Beddoe
Edward Van Sloan
Ben Taggart
Pedro de Cordoba
Wright Kramer
Bertram Marburgh
Robert Fiske
Frank Richards
Kenneth MacDonald
Ernie Adams
Frederick Burton
Edward Earle
Richard Fiske
George McKay
John Tyrrell
Jack Cheatham
Charles Trowbridge
Bert Moorhouse
Sam Harris
Edmund Mortimer
Stanley Brown
Eddie Laughton
James T. Mack
Gohr Van Vleck