Strangers On A Train
Classic Hitchcock film noir in which two men meet on a train trip, and part ways with one of them believing they've agreed to each murder someone the other wished to be rid of.
Not one of Hitchcock's stronger pictures, if you're just starting out with Hitchcock I wouldn't watch it before, say, "North By Northwest", "Rear Window", "The Birds", even "Rope", maybe even "The 39 Steps"... it's not one of the greats, but even the worst Hitchcock is always going to be reliably above a certain quality. To date, if there's a rotten egg in his catalogue, I haven't found it.
This one is a bit more of a slow starter than many of his, and the setup is a bit contrived, but, this one does build to the kind of climax you can rely on from the Master. Definitely has its moments.