This is an old time movie with Cary Grant and Audrey Hepburn. From a production stand point, you can clearly see that it's set in the 1960's, but thematically and acting wise it feels like a lot of Grant's earlier works. The plot works well. Short version: A bunch of folks are looking for some money from Hepburn's ex husband, and they believe that she is the only one who can get it for them, so they threaten her. Grant normally plays good guys, but in this one it is hard to tell what his role is, and the potential villain suits him very well.
Mainly, seeing the chemistry between these two, despite the age difference, is worth the movie alone. The supporting characters are a bit...well, supporting but these two are titans and easily steal the entire show. And the ending is quite delightful because just when you think they've run out of things to throw around in the plot, they hit you with more huge ones totally out of nowhere.
I highly recommend this movie.