This is a dark book. Besides being a mystery, it is a psychological and spiritual thriller. Why spiritual? Because for the second straight book, Lehane portrays a world that is scarred by Evil. Yes, we're dealing with diminished capacity in some cases, but what do think those references to Auschwitz are about? Why is the warden in the story? Can one be insane and evil? Lehane does an excellent job creating a sense of foreboding that keeps you glued to the pages. He draws on King Lear (going mad during a storm), film (the Wicker Man), and recent tragedies (Andrea Yates' killing of her children) to tell the story of Shutter Island. I read this book in two nights because I had to find out what fate awaits our protagonist, Teddy Daniels. Shutter Island is a horror story that goes to the depths of our being.