James Cagney commands an effective group of performers in this excellent WWII spy story. He’s at the center of a particular unit (designated 077, not 007) whose job it is to support those fighting against the occupation. A notable aspect is that both he and the viewer are aware someone within his team is secretly betraying them – and we immediately recognize who this person is. From there unfolds an artfully planned pursuit as they attempt to manipulate him so as to discover how he relays his treachery and to whom. Cagney’s performance is noteworthy, but Annabella ("Madame de Beaumont"), Richard Conte ("O'Connell"), and Frank Latimore ("Lassister") also contribute effectively, maintaining a good level of tension throughout this ninety-minute film. The plot contains considerable action sequences, only a small amount of romance to distract from the central conflict, and provides a palpable sense of how dangerous the lives were for these operatives and their counterparts working in secret during those years. It does require some time to gain momentum, and I would have preferred not to hear Reed Hadley’s overly theatrical narration, but it's definitely something worth seeing.

Source on TMDB