There’s a storm brewing. Everyone’s got something to hide. There’s no escape route. And our heroes are stuck a rock in the middle of the ocean with violently deranged criminals and asylum administrators of dubious motivations, searching for an escaped convict. That Martin Scorsese can turn these clichéd, stock elements into such a gripping, fascinating film for a full feature’s worth of running time is a testament to his amazing skills as a director, and his obvious love for the many pulpy sources he relishes referencing here.

Less fortunately, Shutter Island runs for a good 30 minutes beyond the ideal running time for a taut thriller like this. With a solid movie practically in the bag, that overlong extension, and the twist that initiates it, sends this potboiler roiling right over the sides and all but ruins the whole exercise.

Scorsese’s current leading man of choice, Leonardo DiCaprio, stars in his fourth straight film for the director as Teddy Daniels, a hardboiled U.S. Marshal and World War II veteran. Daniels opens the movie with his new partner, Chuck (Mark Ruffalo), on a boat headed for the Ashecliffe correctional facility. Ashecliffe is an Alcatraz-like prison for the criminally insane fashioned out of an old Civil War fort on an island off the New England coast. A prisoner has disappeared under extremely mysterious circumstances, but the staff, led by the overly friendly Dr. Cawley (Ben Kingsley) and the sinister Dr. Naehring (Max von Sydow), seems strangely reticent to give the marshals the information they need to conduct their investigation.