Chelsea Lerman wakes from a sixteen-week coma with a shattered memory. Following the brutal attack that left her life in tatters, Chelsea learns her best friend Maddie Gray was murdered. Left with only fragments of memory-and none at all about the crime-she is certain she wouldn't kill Maddie. But the police aren't looking for who did it, because they already have a prime suspect...Chelsea. The only way to prove her innocence is to figure out who she is, explore her faded past, and unlock her blocked memories. The truth she seeks might be deadly. Chelsea realizes if she didn't kill Maddie, someone else did. If she has any hope of reclaiming her life, she has to find out who did it...and why. However, her friends, family, and the police aren't convinced her memory loss is genuine, so she's forced to undertake the dangerous search alone. Plagued by a sense of being watched and a series of mysterious "accidents," and unsure who to trust, Chelsea is running out of time. Can she unmask Maddie's murderer before she becomes the next victim?