Boris Karloff

Character: James Lee Wong

Grant Withers

Character: Police Capt. Sam Street

Maxine Jennings

Character: Myra Ross

Evelyn Brent

Character: Olga Petroff / Countess Dubois / Sophie Dome

George Lloyd

Character: Devlin

Lucien Prival

Character: Anton Mohl

John St. Polis

Character: Carl Roemer

William Gould

Character: Theodore Meisle

Hooper Atchley

Character: Christian Wilk

John Hamilton

Character: Simon Dayton

Wilbur Mack

Character: Russell

Lee Tung Foo

Character: Tchin

Lynton Brent

Character: Tommy

Grace Wood

Character: Mrs. Roemer

Frank Bruno

Character: Lescardi (uncredited)

Ed Cassidy

Character: Ambulance Doctor (uncredited)

Wheaton Chambers

Character: Chemistry Lab Director (uncredited)

Clancy Cooper

Character: Warehouse Man (uncredited)

George DeNormand

Character: John (uncredited)

Lester Dorr

Character: Coroner (uncredited)

Herbert Evans

Character: Wilk's Butler (uncredited)

Dick Reinhart

Character: Dock Worker (uncredited)