This is a pretty bog-standard tale, and you've almost certainly seen it done before. Two men who fall in love with the same woman during wartime. Claude Rains plays the stodgy but noble-minded husband while Cary Grant is the suave outsider. Yadda, yadda, yadda.
What is absolutely WONDERFUL about this movie is that the studio tried to save money by recycling scenes from an earlier, silent version of the same (?) film. On paper it made a sort of sense, the earlier film had enjoyed a bigger budget with lots of extras and so on. Unfortunately no-one took into account the film stock and frames per second differences between the two films.
So there you are, watching what seems like a low-budget pot boiler. Suddenly you're thrust into a blurry, gritty shot of hundreds of natives moving VERY quickly and jerkily for a couple of seconds. And then we're back to normal tempos and film stock.
OK, it's not much to write home about but it's quite a fun effect.