I had heard about Dennis Lehane because he is also one of the writer's for the best television series ever "The Wire". The producers chose writers for that show from people who wrote succesful genre fiction local to the urban northeast. Dennis Lehane's area of expertise is Boston.
However, Shutter Island, actually takes place on a small island outside of Boston. So it doesn't draw too much on local flavour. The island is home to a prison for the criminally insane. It's 1948 and two U.S. Marshals have been sent to the island because one of the patients has escaped. Things are weird right from the start, particularly how nobody seems all that freaked out. They get much weirder.
I am not going to go into any detail because I would say this book is good enough to recommend and part of the pleasure of the read is figuring out what is going on. Sometimes when you don't know what kind of a book a book is, what boundaries are acceptable given the genre and setting, you can be critical while you are reading it and then realize 50 pages later that what was going on was actually quite cool. Now, I don't like a book where you finish and then look back and think that was actually kind of interesting (this is even worse with movies). I want to be entertained while I am reading it and if I am constantly critical then I am not being entertained.
Fortunately, this is not the case with Shutter Island. The characters are interesting, the dialogue gripping and the setting is fantastic. There is enough weirdness, action, intrigue and mystery to keep you hooked. There were some false spots and sometimes the writing was a bit too florid (a common problem even among the better American authors these days; sparsity, people, sparsity!). Overall, though, a great, quick read. Recommend it for the plane or the beach or a rainy day with nothing to do.