A hurricane is approaching and patient Rachel Solando escapes from an insane asylum that's located in an island. She didn't try to swim away because the current would have killed her and washed her ashore. So, where is she? That's what U.S. Marshalls Edward "Teddy" Daniels (Leonardo DiCaprio) and Chuck Aule (Mark Ruffalo) are trying to find out.
Throughout their investigation they begin to wonder if Solando really did escape. Does a Rachel Solando even exist? Perhaps it's a trap. Someone wants them on that island and isn't going to let them escape. And with the hurricane nearby they couldn't even if they wanted to.
That's the mystery in director Martin Scorsese's first film since 2006's The Departed, the movie for which he finally won an Academy Award. Like The Departed and even his 1991 film, Cape Fear, it's a thriller that'll have audiences on the edge of their seat. However, it is the weakest of the three. If this movie has one flaw (and it's only ONE flaw) it's that it relies too much on the mystery. Once you know the ending there's no reason to re-watch the film. It's two hours and twenty minutes of DiCaprio running around a mental institute. Aside from two or three humorous scenes nothing distracts the plot. It's on autopilot. So, it's a really good movie but a B-plot away from being great.