It's easy to fall into Teddy's mind and become infected with his paranoia right from the beginning, too see danger everywhere you look. As a reader, I enjoy this type of writing, as I generally read to become one with the characters.

There isn't a lot of quick, battle-like action in Shutter Island, but I find that the slower burn of bits and pieces, clues that may or may not be actual clues, much more effective in building the tension than the all out "fight for your life" scenarios in other types of stories.

To me, the book is well-written, and the characters are well-rounded. The ending is surprising the first time you read the book, and all the little details here and there are wrapped up by the last page. In addition, the book has a high re-read value and will deliver just as much on subsequent readings as on the first one.