Once Upon a Honeymoon

Katie O'Hara, an American burlesque performer masquerading as socialite Katherine Butt-Smith, is about to marry Austrian Baron Von Luber. Pat O'Toole, a foreign correspondent, suspects the Baron's Nazi sympathies and tries to coax information from Katie by deceit, but Von Luber quickly warns him off. The looming wedding unsettles O'Toole, who remains convinced there is a dangerous lie behind the elegant facade.

Pat O'Toole presses his suspicions and attempts to slip information from Katie by deceit, but his bluff fails to shake the couple. Von Luber's cool menace warns Pat that he is crossing a line. Katie continues toward the wedding with guarded hope and growing unease.

In Prague, Katie and Von Luber marry, cementing their alliance as Europe tightens on the eve of war. Pat O'Toole watches from the shadows, trying to confirm his worst fears about Von Luber's loyalties. The union binds her to a dangerous operative just as conflict looms.

Following the German occupation of Czechoslovakia, the Baron's path takes him and Katie to Warsaw, where he begins selling arms to General Borelski. The General tests the weapons and discovers they are defective, planning to alert his government. The Baron maintains control with charm while the danger of exposed schemes grows.

When the Germans invade Poland, the Baron is arrested on suspicion but reassures Katie that no one will bear witness against him. He relies on manipulation and fear to keep danger at bay. Katie stays by his side, unsure of what she can do.

Soon after, the General Borelski is assassinated along with a young Nazi the Baron has chosen to sacrifice. The slayings tighten the net around the Baron and escalate the consequences for everyone connected to him. The act signals the occupiers' increasing willingness to strike at the Baron's network.

While the Baron remains in jail, Katie and Pat decide to flee the country. Katie secretly gives her passport to her Jewish maid Anna so that Anna and her children can escape; they travel through Norway, the Netherlands, Belgium and finally Paris as the net closes in. The journey highlights the peril civilians face as war spreads.

In Paris, they meet Gaston Le Blanc, an American counterintelligence agent posing as a photographer. Le Blanc persuades Katie to return to the Baron and work as a spy, turning desperation into a dangerous assignment. The plan deepens the web of espionage surrounding them.

Von Luber grows suspicious of Katie's persistence, and O'Toole reluctantly agrees to broadcast pro-Nazi propaganda after the Baron threatens to hand Katie over to the Gestapo. American counterintelligence has also asked him to betray the Baron, raising the stakes of every choice. The atmosphere is tense as loyalties blur.

O'Hara is found with Le Blanc, who is shot by two Nazi agents, and Anna helps Katie escape from the hotel. The violence underscores how far the net has closed and the danger facing everyone around the Baron's circle. Anna's courage becomes a lifeline in the chaotic escape.

O'Toole goes on the air, but Katie arrives at the studio and disrupts the broadcast, cleverly helping to make it look as if the Baron is trying to overthrow Hitler. The ploy forces the authorities to react and shifts momentum in their favor, at least temporarily. Pat and Katie maneuver toward safety despite mounting risk.

The ruse leads to the Baron's arrest, and Pat and Katie manage to slip away from Paris with safety within reach. They carry the memory of the Baron's duplicity and the cost of resistance. Their future remains uncertain, but they are free for the moment.

They board a ship for America, but the Baron unexpectedly reappears on deck. The two lovers struggle with the Baron's power to charm his way out, and he falls overboard during the confrontation. The Captain orders a search, but when Katie reveals that the Baron cannot swim, the ship turns back toward America.