Fans of experimental literary thrillers will devour S.J. Watson’s chilling debut Before I Go to Sleep (HarperCollins, $25.99). Narrator Christine suffers from a debilitating form of amnesia: she can retain new memories during the day, but everything vanishes while she sleeps. Totally dependent on her husband to fill in the gaps, she must relearn her identity each time she wakes. Recovery seems hopeless—until an energetic young doctor urges Christine to keep a secret daily journal and phones her every morning to remind her where she’s hidden it. Watson, an audiologist, penned the novel (told through Christine’s journal entries) between all-night shifts at a London hospital, and the result is a heady combination of cutting-edge memory theory and breathless, old-fashioned suspense.