In a Scottish sanitarium, a brilliant research psychiatrist works on a treatment for dementia praecox. He falls for his altruistic female lab assistant and they begin a passionate, tragic relationship.
| Actor | Role |
|---|---|
 James StephensonDr. Paul Venner | Dr. Paul Venner |
 Geraldine FitzgeraldDr. Mary Murray | Dr. Mary Murray |
 Donald CrispDr. Drewett | Dr. Drewett |
 Barbara O'NeilMiss Leeming | Miss Leeming |
 Montagu LoveDr. Blake | Dr. Blake |
 Sig RumanProfessor Herman Von Reiter | Professor Herman Von Reiter |
 G.P. HuntleyDr. Thornton | Dr. Thornton |
 Richard AinleyDr. Hale | Dr. Hale |
 Bruce LesterDr. Bentley | Dr. Bentley |
 Leonard MudieMr. Tom Foster | Mr. Tom Foster |
 Doris LloydMrs. Foster | Mrs. Foster |
 Frank ReicherDr. Esterhazy | Dr. Esterhazy |
 Hermine SterlerMiss Hoffman | Miss Hoffman |
 Billy BevanChivers | Chivers |
| CClare VerderaMiss Dennis | Miss Dennis |
 Crauford KentDr. Corliss | Dr. Corliss |
 Alec CraigJeweler | Jeweler |
 Mary TaylorMrs. Kent a Patient (uncredited) | Mrs. Kent a Patient (uncredited) |
 Bette DavisNot listed | Not listed |