1. What Happened To The Money? - Psycho (1960)
At the beginning of Alfred Hitchcock's all-time classic Psycho, Janet Leigh's secretary character, Marion Crane, steals $40,000 in an attempt to help her divorced boyfriend Sam Loomis. Although the money's intention is purely that of a MacGuffin - one to get the character to make an escape and check in at the infamous Bates Motel - we never find out what happens to the whopping sum that gets the plot moving in the first place. Once the story changes directions in the second act and Leigh is shockingly bumped off in cinema's most famous shower sequence, the movie's focus switches instead to Anthony Perkins' demonic Norman Bates. The money is thrown out by accident and submerged in Crane's car when Norman dumps it into the swamp, where it is later pulled out in the film's iconic final shot. It remains largely forgotten, though, as the plot dwells on more pressing matters, and we're never told explicitly what happened to the $40,000 - or if it ever finds its way back to its rightful owner. Can you think of any other movie plot threads that were never resolved? Let us know in the comments section below.