Shutter Island is a psychological thriller based on Dennis Lehane's novel of the same name. Troubled U.S. Marshal Teddy Daniels and his new partner, Chuck Aule, are assigned to investigate the mysterious disappearance of a mentally unstable child murderer from Ashecliffe Hospital, a high-security psychiatric institution for criminally insane patients on Shutter Island.
Behind the hospital's imposing stone walls, however, Teddy uncovers increasingly disturbing clues suggesting serious ethical violations and suspects that the institution's enigmatic chief psychiatrists are concealing a crucial truth. When a violent storm traps both the patients and the investigators on the island, Teddy begins to suffer from crippling migraines and haunting nightmares that force him to confront traumatic memories from his past. As the line between reality and illusion becomes increasingly blurred, Teddy's own sanity is called into question.