| Actor | Robert Beatty (as Dr. Paul Rankin), Mervyn Johns (as Dr. Bruckner), Karel Stepanek (as Prof. Inman), Alan Wheatley (as M.W. Kennedy), Anthony Eustrel (as Dr. Richard Forrester), Ronald Adam (as Ingram) |
| Actress | Nova Pilbeam (as Tracy Hart), Margaretta Scott (as Sister Johnson), Marie Lohr (as Mrs. Coles) |
| Writer | Jack Whittingham |