"Shutter Island" won't surprise most filmgoers: I predicted the ending of "Shutter Island" before I even saw the film. That being said, the roads that lead to the ending keep the movie semi-interesting. Leonardo DiCaprio plays Teddy Daniels, a U.S. Federal Marshal who is called to the island to investigate the disappearance of one of the mental facility's patients. Fellow Marshal Mark Ruffalo goes with him, and while there they meet the facility's overseer, played by Ben Kingsley, and the residents that live there. On his search for the missing patient, Teddy has numerous flashbacks from when he was a soldier in World War II, which appear to stem from his migraine headaches.
Michelle Williams ("Brokeback Mountain") plays Leo's deceased wife, shown only in flashbacks, and Ted Levine (Capt. Stottlemeyer from "Monk") has a small role as a Warden. Both Leo and Ben Kingsley are excellent in their roles, and Mark Ruffalo has a decent part as well. The mental hospital's "patients" are all exceedingly creepy, and we are introduced to some of them as the story unfolds.
The trailer for this movie definitely did not reflect the movie as a whole. There are tons of flashbacks that, for the most part, were not included in it, and the trailer made the movie look like it was going to be far scarier than it was. There are even some moments of humor—at one point, one of the patients in Ward C, where the most disturbed patients are kept, jumps Leo's character, only to hit him and say "Tag, you're it!"
However, I would say Maybe see this movie. I didn't like that I had been able to guess the ending, but I have to admit that the details surrounding the ending were interesting and the movie definitely tries to screw with your mind. On the other hand, a few audience members definitely did not see the ending coming, as I heard a few gasps when the crucial plot twist happened near the end. The reason I say "Maybe" see this movie is because of the superb acting of Leo and Kingsley, and the fact that, for the most part, the story is interesting, and moves quickly - there were only a few scenes in which I was checking my watch. The movie is definitely not as good as the trailer makes it appear to be, but for some moviegoers, it might be worth a second look.