What if your mother sleepwalked out of your house one night and disappeared? When Annalee Ahlberg disappears, her college age daughter Lianna is guilt ridden; she heard nothing when Annalee left the house. Lianna is drawn to the detective assigned to the case, a sleepwalker who knew her mother from time at a sleep clinic; her younger sister, Paige, may be sleepwalking too; and what about the neighbors who may have known more than they are saying? When all is revealed, I thought I should have seen that coming, but I didn’t. A well-told tale displaying Bohjalian’s thorough research and story-telling skills.