This is a really entertaining and funny movie, and a great William Powell vehicle. He sort of plays his "Thin Man" character (well maybe more than "sort of"), this time paired with Ginger Rogers who holds her own as his wants-to-get-married girlfriend. Powell plays the witty, sophisticated mystery-solver and has some of the best lines in the movie (e.g., "That's the silliest thing you've ever said, and that's covering a lot of ground"). It's a twisted (in a good way) mystery storyline and I'd be surprised if you can solve it before the end.
Some familiar faces featured include Paul Kelly, Ralph Morgan, J Farrell MacDonald, and Gene Lockhart as the butler. Watch it if you get a chance.
Rogers to Powell: "You're wonderful." Powell to Rogers: "That's common knowledge." And he is.