- Author:
- Helen McCloy
- Adapted by:
- John Hopkins
- Producer:
- Vivian A. Daniels
- Designer:
- Kenneth Lawson
- Dr. Basil Willing:
- Andrew Osborn
- Faustina Crayle:
- Diane Clare
- Gisela von Weber:
- Julia Arnall
- Alice Aitchison:
- Moira Redmond
- Mrs. Lightfoot:
- Joyce Heron
- Arlene Murphy:
- Dorothy Gordon
- Mrs. Fitzgerald:
- Zoe Hicks
- Meg Vining:
- Sandra Michaels
- Beth Chase:
- Ingrid Sylvester
- Dorothea Chase:
- Mona Bruce
- Peter Chase:
- Victor Lucas
- Raymond Vining:
- Oscar Quitak
- Mr. Watkins:
- Geoffrey Wincott
- Inspector Haskell:
- Leonard Williams
- Det.-Sgt. Beaumont:
- Basil Beale
- Hotel clerk:
- Anthony Roye
- Mr. Noble:
- Victor Tandy
