The Big Clue Everyone Missed Early In Shutter Island

2010's Shutter Island, which follows Deputy U.S. Marshal Teddy Daniels as he investigates the disappearance of a missing psychiatric patient only to discover a much darker truth by the end, may not be director Martin Scorsese's best feature, but it's certainly one of his wildest. For fans of the film, the true joy isn't in its big reveal — it's in rewatching the movie for clues.