From the description:
"“Anexceptional thriller. It left my nerves jangling for hours after I finished thelast page.” —Dennis Lehane, New York Times bestselling author of Moonlight Mile
S. J. Watson makes his powerful debutwith this compelling, fast-paced psychological thriller,reminiscent of Shutter Island and Memento, in which an amnesiac who,following a mysterious accident, cannot remember her past or form newmemories, desperately tries to uncover the truth about who she is—and whoshe can trust."
So, 3.8 stars on over 1000 reviews, with a bunch (194, nearly 20%), negative. 515 pages, and a buck more than usual