The time is 1954. The place is a fog-shrouded, desolate island off the coast of Massachusetts. There, in buildings dating back more than a century, psychiatrists attempt to treat …and possibly heal …a dangerous assortment of patients.

Marshal Teddy Daniels enters this shadowy world because one of the patients (although he keeps calling them 'prisoners') has mysteriously vanished.

The more he investigates, the deeper the mystery gets and the harder it becomes to separate the sane from the insane... or the victims from the perpetrators.

Since the start of his career, director Martin Scorcese has explored people and violence with films like "Taxi Driver," "Raging Bull," "Goodfellas" and the Oscar-winning "The Departed."  With "Shutter Island" Scorcese navigates the shadowy, occasionally invisible line between reality and imagination:

"It was revealed to be many different realities and, without giving away too much, there are certainly different levels with the characters," Scorcese said. "The doctor appears one way, in scene four it's another way, in scene 10 it's something else and it is something that intrigued me a great deal so I sort of gave myself to the material along with the actors. I didn't quite know where we would be at any given time and I think we discovered this as we went along."

 

"This film depends on you not knowing where you are at in any given situation," said Leonardo DiCaprio.

He said even though they had all read the script, he and the rest of the cast were often kept off-balance while making the film because of those multiple realities.

"It was like a giant jigsaw puzzle and the more we started to unearth and peel back the onion of who this guy was and what happened to him in the past and trying to truly understand the reason why he would be so obsessed with a specific case …once we start to uncover these things about him we realized that once we explain one set of circumstances we needed to go even further with another set of circumstances," he continued.  "For one thing to be believable we needed to push another story line even further. We realized we had to push certain boundaries and there were a few weeks there that were, I have to say, some of the most hard-core filming experiences I have ever had and it was pretty intense."

Mark Ruffalo plays Teddy's partner in the investigation and Sir Ben Kingsley is Dr. Cawley, the psychiatrist who runs the hospital. Kingsley was fascinated by how the story explores mental health care from half-a-century ago when techniques now viewed as barbaric were commonplace.

"What did emerge was an extraordinary level of tenderness between the characters," he said. "Even though, as Leo pointed out, it looks like a thriller, the glue that holds it together is varying levels of tenderness: for your wife, for your child, for your patient, for your friend."

Mixed in are harrowing memories shared by a generation of World War II veterans, like DiCaprio's character, as well as the Cold War tensions affecting so many lives in the 1950s. DiCaprio admits that talking about the film is difficult because revealing too much could spoil surprises that await the audience.

"This film is very much a thriller in a lot of ways with a surprise ending and with terrifying elements to it and very much a genre piece; but at the end of the day it is what Martin Scorcese does best and that is portraying something about humanity and human nature and who we are as people," he said. "That is what makes it stand out and different than just being a normal genre piece …to me, anyway."

The "Shutter Island" cast also features Michelle Williams as the Marshal's tragic wife. Emily Mortimer and Patricia Clarkson are characters he encounters at the hospital trying to unravel the mystery (before it unravels him); and screen veteran Max Von Sydow plays a brilliant psychiatrist whose own past may harbor dark secrets.