***SPOILERS*** Not wanting to be a hero shot down USAAF pilot Ben "Hard Luck" Hollister, Peter Brown, is recruited by his fellow US POWS to escape from the German prison camp and make it back to England via Nancy France. The very fact that Ben can speak French like a native was the only reason he was chosen. Not the fact that he's a 1st class screw up in him being shot down in three of the six bombing missions he flew over Nazi occupied Euope.
As things turned out Ben in fact does escape from the German POW camp- with a load of secret information hidden in his boots-and at the Hamburg train station he runs into French Resistance fighter Beret, Telly Savalas, who's also traveling to Nancy Frace his hometown. Knowing that he's an escaped US POW Beret gives Ben some important tips in avoiding the Gestapo by acting more like a Nazi then even Adolph Hitler. This all works to perfection for Ben and just when his train is about to stop in Nancy France the pretty German Fraulein Ursula,Ula Jacobsson, that he struck up a conversation with, at Beret's insistence, at the Hamburg train station asks Ben a simple question: Are you a member of the German Gestapo?
***SPOILER*** In her former boyfriend being a member of the dreaded Nazi Gestapo Ula in seeing Ben together with Beret innocently thought that he was a Gestapo man in that Berte himself is one! And not only that Beret's involved in capturing escaped allied POWS after he finds out their contacts in the French Resistance movement by befriending them and winning over their confidence, by masquerading as a French resistance fighter, like he did with Ben!
As fate would have it Ben in getting tips in avoiding being captured by Beret, with Ursala tipping him off on Berets true motives, he eventually was able to make his escape back to Britian with the important information that would change the course of the war in Europe in the allies favor. And he had both German and pro-Nazis Ursala and Beret to thank for it.