Humble stamp dealer Otto Becker has little to do with international politics, so when he receives a surprise visit from his estranged twin brother and Nazi spy, Baron Hugo von Detner, his world is thrown into turmoil. Threatening Becker with deportation, Hugo forces him to use his shop as a front for espionage.
| Directing | Jules Dassin | Director |
| Production | Irving Asher | Producer |
| Camera | Harry Stradling Sr. | Director of Photography |
| Editing | Frank E. Hull | Editor |
| Art | Cedric Gibbons | Art Direction |
| Writing | Paul Gangelin | Screenplay |
| Writing | John Meehan Jr. | Screenplay |
| Sound | Lennie Hayton | Original Music Composer |
| Art | Edwin B. Willis | Set Decoration |
| Costume & Make-Up | Howard Shoup | Costume Design |
| Art | Stan Rogers | Art Direction |
| Costume & Make-Up | Jack Dawn | Makeup Artist |
| Costume & Make-Up | Sydney Guilaroff | Hairstylist |
| Sound | Douglas Shearer | Sound Director |
| Writing | Lothar Mendes | Story |
| Sound | Daniele Amfitheatrof | Music |
| Sound | Bronislau Kaper | Music |
| Sound | Sol Kaplan | Music |
| Sound | David Snell | Music |
| Crew | Duke York | Stunts |
| Sound | Wally Heglin | Orchestrator |
| Sound | Joseph Nussbaum | Orchestrator |
| Sound | Leonid Raab | Orchestrator |
