Once Upon a Honeymoon (1942) on Netflix

Plot summary

Katie O'Hara, an American burlesque performer traveling under the name Katherine Butt-Smith, is preparing to marry Austrian Baron Von Luber. Pat O'Toole, a foreign correspondent, suspects the baron of Nazi sympathies and tries to draw information from Katie by trickery, until Von Luber warns him off. O'Toole follows the couple to Prague, where the marriage takes place, and then to Warsaw, where the baron sells weapons to General Borelski. O'Toole warns the general against trusting the baron. When the general test fires the guns and finds them faulty, he plans to inform his government. The German invasion of Poland follows.