“Shutter Island” by Dennis Lehane
Source: Bought from Amazon
Summary from Goodreads:
In a masterful departure from the Boston-based hard-boiled mysteries he’s known for, New York Times bestselling author Dennis Lehane (Mystic River) offers an atmospheric psychological thriller set in a 1950s asylum for the criminally insane. It’s 1954, and up-and-coming U.S. marshal Teddy Daniels is assigned to investigate the disappearance of a patient from Shutter Island’s Ashecliffe Hospital. He’d been gunning for an assignment on the island for reasons of his own — but before long he wonders whether he hasn’t been brought there as part of a twisted plot by hospital doctors whose radical treatments range from unethical to illegal to downright sinister. Teddy’s code-breaking skills soon provide a promising lead, but the hospital refuses him access to records he suspects would break the case wide open. As a hurricane cuts off communication with the mainland, more dangerous criminals “escape” in the confusion, and the puzzling, improbable clues proliferate, Teddy begins to doubt everything — his memory, his partner, even his own sanity.