Shutter Island is set in 1954 and follows U.S. Marshal Teddy Daniels (played by Leonardo DiCaprio) as he investigates the disappearance of a patient from a psychiatric hospital on a remote island. As Teddy digs deeper into the mystery, he uncovers a web of secrets and conspiracies that challenge his perceptions of reality. The film features a complex and layered narrative, replete with twists and turns that keep viewers on the edge of their seats.