Imprisoned during the Spanish Civil War, John "Kit" McKittrick is released when a New York City policeman pulls some strings. Upon returning to America, McKittrick hears that a friend has committed suicide, and he begins to smell a rat. During his investigation, McKittrick questions three beautiful women, one of whom has a tie to his refugee past. Pursued by Nazi operatives, McKittrick learns of the death of another friend, and begins to suspect the dark Dr. Skaas.
| Production | Robert Fellows | Producer |
| Writing | Warren Duff | Screenplay |
| Editing | Robert Wise | Editor |
| Directing | Richard Wallace | Director |
| Camera | Nicholas Musuraca | Director of Photography |
| Writing | Dorothy B. Hughes | Novel |
| Sound | Roy Webb | Original Music Composer |
| Sound | James G. Stewart | Sound Re-Recording Mixer |
| Art | Darrell Silvera | Set Decoration |
| Art | Mark-Lee Kirk | Art Direction |
| Art | Albert S. D'Agostino | Art Direction |
| Crew | Vernon L. Walker | Special Effects |
| Art | Harley Miller | Set Decoration |
| Art | Van Nest Polglase | Production Design |
| Sound | Bailey Fesler | Sound Recordist |
| Sound | C. Bakaleinikoff | Music Director |
| Costume & Make-Up | Edward Stevenson | Costume Designer |
| Directing | Sam Ruman | Assistant Director |
