Claire wakes in a hospital room in the Florida Keys. She has no idea how she got there or why. The loss of so many memories is paralyzing. Some things she can piece together by looking at old photos saved by her husband, Charlie, and her best friend, Rachel, and by combing through boxes of letters and casual jottings. But she senses a mystery at the center of all these fragments of her past, a feeling that something is not complete. Is Charlie still her husband? Is Rachel still her friend? Told from alternating points of view, the story unfolds as the smudge that covers Claire’s memory is gradually, steadily wiped away, until finally she can understand the why and the how of her life.