Annalee Ahlberg is an architect who lives in Vermont with her husband, Warren, and two daughters, Lianna and Paige. Annalee is also a sleepwalker. While slumbering Annalee has done things like spray- painting hydrangeas with silver paint - almost killing them; and climbing onto the bridge over the Gale River, stark naked. After Annalee was rescued from the bridge by her daughter Lianna, the somnambulist attended a sleep clinic for an extended time and got appropriate medication.
Annalee's sleepwalking episodes always seemed to occur when her husband was away, so Warren hasn't gone out of town on business for years. Now that Annalee's sleepwalking appears to be under control, Warren - an English professor - decides to attend a poetry conference out of state....and on the first night he's gone, Annalee disappears.
An extensive search uncovers a scrap of fabric from Annalee's nightshirt near the Gale River, and the police speculate that she drowned. Annalee's body isn't recovered, however, and the family holds out hope that she'll return. Meanwhile, Warren continues teaching, but drinks himself to sleep in front of the TV every night. And Lianna takes a leave from her senior year at Amherst College to assist her dad and help her sister Paige - an athletic middle-schooler who swims and skis competitively.
Soon after her mother vanishes, Lianna starts dating Gavin Rikert, a handsome 32-year-old detective assigned to Annalee's case. Gavin tells Lianna that he's also a sleepwalker, and had met Annalee at the sleep clinic. He also confides that he and Annalee formed a two-person 'support group' and sometimes met for coffee and conversation. Lianna suspects that Gavin slept with Annalee - who was a beautiful, statuesque blonde - but he denies it.
Nevertheless, Lianna remains suspicious of Gavin and Annalee, and becomes even more concerned when she learns that both of them are 'sexsomniacs' - people who crave sex while asleep. Lianna comes to learn that sexsomniacs sometimes leave their homes - while fast asleep - to find sex partners.....and even speculates that Annalee might have sex-slept with her friends' husbands. Because of certain revelations, Annalee wonders if Warren is Paige's father....and comes to conjecture about foul play in Annalee's disappearance.
Lianna is the story's narrator, and we follow her as she smokes pot, buys Mexican wraps for dinner, guides her tipsy dad from the couch to his bed at night, drives Paige to her swimming and ski practices, calls her friends at Amherst, does magic shows for children's birthday parties, gets blind drunk on a date with Gavin - and does 'detective work' (blatantly invading people's privacy) to investigate Gavin's relationship with Annalee. Lianna also keeps an eye on Paige, who compulsively looks for her mother - even to the point of searching the river. Lianna's narration is interspersed with (what seems like) the diary entries of an unidentified somnambulist, detailing episodes of sleep-sex.
We eventually learn what happened to Annalee, and the book's climax and epilogue are quite a revelation.
I found Lianna's account to be a bit meandering and repetitive, but the story held my attention and I learned a lot about sleepwalking. Some of Lianna's behavior put me off, but I did like the scenes where she practiced and performed magic tricks, which was a nice respite from the darker parts of the story.
I'd categorize the book as a family saga/offbeat mystery and would recommend it to fans of these genres.