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Boris Karloff as Prof. Morlant |
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Cedric Hardwicke as Broughton |
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Ernest Thesiger as Laing |
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Ralph Richardson as Nigel Hartley |
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Dorothy Hyson as Betty Harlon |
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Anthony Bushell as Ralph Morlant |
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Kathleen Harrison as Kaney |
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Harold Huth as Aga Ben Dragore |
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D.A. Clarke-Smith as Mahmoud |
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Jack Raine as Davis the Chauffeur (uncredited) |
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George Relph as Doctor (uncredited) |
| Writing | Roland Pertwee | Writer |
| Writing | Frank King | Theatre Play |
| Writing | Rupert Downing | Adaptation |
| Directing | T. Hayes Hunter | Director |
| Writing | John Hastings Turner | Writer |
| Writing | Leonard Hines | Theatre Play |
| Production | Geoffrey Boothby | Unit Manager |
| Art | Alfred Junge | Art Direction |
| Sound | Peter Birch | Sound Recordist |
| Directing | R. Lyons | Assistant Director |
| Editing | Ian Dalrymple | Editor |
| Camera | Günther Krampf | Director of Photography |
| Costume & Make-Up | Heinrich Heitfeld | Makeup Artist |
| Editing | Ralph Kemplen | Editor |
| Production | Michael Balcon | Producer |
| Sound | Louis Levy | Original Music Composer |
