A sense of unease pervades Scorsese's latest work as we follow US Marshal Teddy Daniels (Leonardo DiCaprio, who else) in his investigation of a 1950s mental institution for criminals and the murderess who managed to escape.

Teddy doesn't trust anyone - not Dr. Cawley (Ben Kingsley) who runs the show, not the orderlies, not the nurses, not even his own partner Chuck (Mark Ruffalo). How much you enjoy this film relies on how much you trust the director - get sucked in too much to Teddy's investigation of the horrific, inhumane labotomies that he believes are being carried out and you may leave feeling hard done by, come the closing credits. Especially if you like closure with your popcorn - Scorsese could have left it more ambiguous but as it is, there is scope for plenty of post-cinema discussion.

Flashbacks and dream sequences illuminate the haunting background to our anti-hero - Nazi concentration camps, the slaughter of German guards, the death of his wife Dolores, the woman who drowned her three children.

The cinematography is brilliantly drab and disconcerting and it must have been fun to let the elements run riot over the Shutter Island set. The music is classic thriller but there are surprisingly few cheap jumps. Instead the script, based on the novel by Dennis Lehane, explores the terrifying prospects of being caught in a Catch 22 - the more that you protest you are the sane, the likelier you will be thought mad. Another recurring theme is the creation of a fictional world which is safer for the criminals to retreat to than reality. Rachel, who escaped, is said to treat the other patients and staff as milkmen, delivery men, postmen.

DiCaprio reminded me too much of DiCaprio playing other roles, such as DiCaprio in The Departed (Scorsese). He didn't seem to own the character as much as he did in, say, The Aviator (Scorsese again). Ruffalo was superbly understated in his sidekick role, particularly in the final scenes and Kingsley, well, Kingsley played a creepy character we can't entirely like even if he's a good guy.

Scorsese isn't remaking the thriller genre here, but if you like your shudders with a twist Shutter Island is a curious, intense piece of cinema.