BERLIN -- Martin Scorsese's "Shutter Island" is a remarkable high-wire act, performed without a net and exploiting all the accumulated skills of a consummate artist. It dazzles and provokes. But since when did Scorsese become a circus performer?

The movie certainly keeps you in its grip from the opening scene: It's a nerve-twisting, tension-jammed exercise in pure paranoia and possibly Scorsese's most commercial film yet. With a top cast hitting their marks with smooth efficiency, "Island" looks like a boxoffice winner. Paramount opens the film domestically Friday Feb. 19.

Laeta Kalogridis' screenplay is based on a novel by Dennis Lehane, whose blue-collar crime novels have been turned into such movies as "Gone Baby Gone" and "Mystic River." But this story clearly derives from memories and images of old movies -- from 1950s Gothic mysteries and Cold War-era paranoia thrillers to 1960s movies cranked out by the Roger Corman factory (where Scorsese once toiled), especially its Edgar Allan Poe/Vincent Price chillers.

You get an isolated island, howling weather, mad scientists, an ex-Nazi, tough cops, deranged patients and a penal hospital with crowded, filthy cells and corridors stretching forever -- possibly beyond sanity.

Scorsese has given himself a film student's puzzle: Try to make a '50s-era thrill ride with today's techniques and technology. One senses his childlike delight behind every camera move and jump cut. As his audience squirms, he's in movie heaven.

From the opening music chords, supervised by Robbie Robertson from existing source material, a sense of doom settles over the film's characters. In 1954, two U.S. marshals -- Teddy (Scorsese's go-to star, Leonardo DiCaprio) and his new partner, Chuck (Mark Ruffalo) -- watch the forbidding fortress that is Shutter Island loom larger and larger as their ferry approaches the island's only dock.

In quick order, exposition rolls off the actors' tongues, like in those B-movies that lasted only 70 minutes. Shutter Island is a hospital for the criminally insane. One female psychopathic patient has gone missing, incredibly, from a locked room within the fearsome-looking Ashecliffe Hospital. A hurricane is approaching. The guards and psychiatrists then greet the lawmen with hostility and evasions. Everything screams, "Go back!"

Teddy gradually warms up to his partner enough to take him into his confidence: He asked for this assignment. Unresolved issues await him on Shutter Island. His nightmares vividly underscore these past traumas. They involve his platoon liberating a concentration camp and witnessing its horrors. They involve the death of his wife and a former Shutter Island prisoner who talked to him about devastating medical experiments and funding by anti-Soviet groups.

In fact, maybe these aren't nightmares at all. During daytime, Teddy experiences flashbacks and the presence of the dead, especially his late wife (Michelle Williams) and a little girl from the camp who asks, "Why didn't you save me?"

The hospital's pipe-smoking chief psychiatrist, Dr. Cawley (Ben Kingsley), preaches the humane treatment of patients. (He won't use the word "prisoner.") But his fellow shrink with a German accent (Max von Sydow) reminds Teddy of the dark side of the medical profession he encountered in the camp.

When the storm hits, chaos reigns. Trees crash into buildings, electrical outages free prisoners, all communication with the mainland is cut off and the two marshals are as much prisoners as the patients.

The story barrels forward into encounters with an escaped prisoner (Patricia Clarkson) hiding on the island and another prisoner (Jackie Earle Haley) who has been severely beaten. Then, suddenly, the escaped female killer (Emily Mortimer) is found -- just like that. Teddy isn't buying it.

The problem, of course, is the viewer is in the same boat. Are Teddy's nightmares and ghosts because of something the warden has slipped into his drink? Are any of these encounters real? If so, which are real and which are ... imaginary?

The big reveal, when it does happen, might be yet another fraud. Teddy certainly clings to his conspiracy theories.

Scorsese is in full control of all three rings of this cinematic circus. Every lesson he learned, from Alfred Hitchcock to Don Siegel, is on display. Nearly every camera move is fraught with excitement. The music, costumes, props and the many rooms and halls of this fortress-prison are designed for maximum emotional impact.

After finally getting that long-sought Oscar for "The Departed," perhaps Scorsese figures it's time to have a bit of fun. He isn't asking to be taken seriously here. This isn't "Taxi Driver" or "GoodFellas" or even "Alice Doesn't Live Here Anymore." It comes closest in his oeuvre to "Cape Fear," but with a more commercial instinct.

Let's hope this is a digression in his illustrious career, a way of playing with what Orson Welles called the "toys" of moviemaking. With Dante Ferretti designing his sets and Robert Richardson behind the camera, Scorsese certainly has the right playmates. Longtime editor Thelma Schoonmaker weaves her magic by bringing images together in such a way that the audience can't quite trust what it sees.

It's a pleasure to experience Scorsese as a circus master. One just hopes he doesn't continue in this vein.

Venue: Berlin International Film Festival
Opens: Friday, Feb. 19 (Paramount)
Production: Paramount Pictures presents a Phoenix Pictures production in association with Sikelia Prods. and Appian Way
Cast: Leonardo DiCaprio, Mark Ruffalo, Ben Kingsley, Michelle Williams, Emily Mortimer, Patricia Clarkson, Max von Sydow, Jackie Earle Haley
Director: Martin Scorsese
Screenwriter: Laeta Kalogridis
Based on a novel by: Dennis Lehane
Producers: Mike Medavoy, Arnold W. Messer, Bradley J. Fischer, Martin Scorsese
Executive producers: Chris Brigham, Laeta Kalogridis, Dennis Lehane, Gianni Nunnari, Louis Phillips
Director of photography: Robert Richardson
Production designer: Dante Ferretti
Music: Robbie Robertson
Costume designer: Sandy Powell
Editor: Thelma Schoonmaker
Rated R, 139 minutes