Despite the presence of Franchot Tone and Ton Conway, "Lost Honeymoon" is a truly dreadful film--with a stupid premise and amazingly bad writing. It made me cringe and I pray that you read this review and think twice about seeing this turkey.
When the film begins, you learn that a British lady has died and her twin children are being kept by her landlady. However, there IS a father--some American named John Gray. So, an amazingly stupid lady (Ann Richards) decides she's going to go to the States to find the man--a guy who married the now dead lady while was stationed in Britain during the war. However, instead of going about this is a sane manner, she decides to tell the Red Cross that she IS the dead woman and gets them to pay for her voyage with the two children. Once she's in America, she seems to automatically know that THE John Gray she wants is the one played by Tone--even though it's a relatively common name and he might not be the one. So, despite having no hard evidence, she strikes like a blitzkrieg--not caring what sort of repercussions there might be.
Now if this isn't bad enough (and amazingly contrived), it turns out that this Gray might just be the one. However (uggh, this is bad writing), he doesn't know if he is or isn't because he had a head injury and six weeks of his life are missing. During that time he MIGHT have gotten married and fathered the kids--but he doesn't know! Later (in yet another badly written twist), he learns that the woman pretending to be his wife is a liar...and he now is in love with her and must have her!!!
The bottom line is that none of this film makes sense. It's built on one dopey premise after another and the movie is one of the most contrived and silly films I've ever seen. The end result is impossible to believe, quite stupid and really a waste of decent actors. Not worth your bothering with this one.