Double-agent Alexander Eberlin is assigned by the British to hunt out a Russian spy, known to them as Krasnevin. Only Eberlin knows that Krasnevin is none other than himself! Accompanying him on his mission is a ruthless partner, who gradually discovers his secret as Eberlin tries to maneuver himself out of a desperate situation.
| Directing | Anthony Mann | Director |
| Writing | Derek Marlowe | Screenplay |
| Directing | Laurence Harvey | Director |
| Production | Anthony Mann | Producer |
| Sound | Quincy Jones | Original Music Composer |
| Editing | Thelma Connell | Editor |
| Camera | Christopher Challis | Director of Photography |
| Camera | Austin Dempster | Director of Photography |
| Art | Carmen Dillon | Art Direction |
| Art | Patrick McLoughlin | Art Direction |
| Production | Harold Buck | Production Manager |
| Production | Eddie Pike | Unit Manager |
| Directing | Jimmy Komisarjevsky | Assistant Director |
| Camera | Austin Dempster | Camera Operator |
| Directing | Elaine Schreyeck | Continuity |
| Production | Maude Spector | Casting |
| Sound | Peter T. Davies | Sound Recordist |
| Sound | Gerry Humphreys | Sound Recordist |
| Costume & Make-Up | Jill Carpenter | Makeup Artist |
| Costume & Make-Up | Anne Box | Hairdresser |
| Costume & Make-Up | Betty Adamson | Wardrobe Supervisor |
| Costume & Make-Up | Pierre Cardin | Costume Designer |
| Writing | Derek Marlowe | Novel |
| Production | Leslie Gilliat | Associate Producer |
| Editing | Stephen Warwick | Assistant Editor |
