For anyone who struggled with trying to make sense of this Dennis Lehane mystery, here is a graphic novel's interpretation that might help shed some light.
Christian de Metter is another one of those award-winning European illustrators who had this book honored in France.
There has been a lot of debate about the ending of Shutter Island. It is said that one picture is worth a thousand words. There are a great many pictures in this graphic novel. Words still escape me.