Leonardo DiCaprio plays a nervy 1954 US Marshal who arrives on Boston’s title island. It’s a maximum security hospital for the criminally insane and he’s there to investigate the apparently inexplicable disappearance of a patient, a child murderer. But how can she have vanished when the only way off the island is by ferry, heavily guarded by the warden (Ted Levine) and his tough-nut cronies? What exactly are the nature of the bizarre treatments concocted by suave and sinister hospital doctors Ben Kingsley and Max von Sydow? And what’s happened to DiCaprio’s deputy (Mark Ruffalo)? Despite the big twist being a little too easy to spot, DiCaprio’s acting is extremely intense, committed and convincing, while director Martin Scorsese delivers an intriguing, well-crafted, supremely sleek and stylish thriller.