Once Upon a Honeymoon stars Ginger Rogers as an American ex-burlesque dancer and social climber who is engaged to be married to Baron Von Luber (Walter Slezak) in Vienna. She currently goes by the name of Katherine Butt-Smith, though her real name is Kathie O'Hara. Fellow American Patrick O'Toole is a journalist interested in the baron's political ties to Hitler. He follows the couple, who marry shortly after leaving Vienna, across Europe and, finally, Kathie realises that her husband is a close ally of the Nazis and seeks refuge with O'Toole. They fake her death but continue to follow him, ending up in Paris where an undercover American spy has a task for Kathie that neither she nor O'Toole is going to like.
This is an odd film, blending tragedy with comedy and not always getting it right. The main plot of a love triangle often feels at odds with the serious nature of the war going on around them. Two really dark moments stick out in my mind: the moment when Kathie gives her passport to her Jewish maid to allow her to flee the country with her two children and puts them on the back of a van to travel to safety then when she and O'Toole are taken by the Nazis and read a notice on a door about forced sterilisation procedures. Moments like this are hard-hitting but do feel out of place in a film that begins with Cary Grant playing with a tape measure as he impersonates Kathie's dress-fitter.
The relationship between Kathie and O'Toole is well-developed enough not to feel rushed and Rogers and Grant play it well. I was less certain about Baron Von Luber's relationship with Kathie - while it was evident why she wanted to marry him, he was underdeveloped in that respect. Not to say that Slezak's performance as the duplicitous baron isn't excellent, it's just that the character isn't as developed as I would've liked. Again, this probably comes from the film being a cross between a comedy and a drama, where the requirements for the third character in a love triangle are somewhat different.
I really enjoyed this one, despite the irregularities in genre and pace. It does descend into propaganda at times but Rogers treats this lightly enough for it not to be too blatant. Her final scenes with Grant on the ship bring the film back to comedy when something incredibly dark has just happened - again, I'm not sure about the tone but I can't fault Rogers and Grant for playing the scene as it was written.