 The film is based on a 1939 West End play of the same title by Barré Lyndon, and stars Nils Asther and Helen Walker with direction by Ralph Murphy.A scientist, Dr. Karell (Asther), has discovered a treatment that can indefinitely prolong his life, using glands stolen from human victims.Having kept his achievement secret for over a century of continuous youth, Karell now has to contend with the curiosity of his new girlfriend Eve (Walker), the increasing guilt of his colleague Dr. Van Bruecken (Schünzel), and a police investigation of his most recent murder.