*Starred Review* Grief is disabling Poppy Lang nearly a year after her husband, Jack, was murdered on a predawn run in Central Park. She's taking a toxic mix of pills and alcohol to help her sleep, then having dreams that morph into nightmares and hallucinations, and she believes that she's being stalked by a man in a hoodie. When an orchid with a mystifying message is found in her apartment, she contacts the detective still working on Jack's case as well as Layla Van Santen, her closest friend, who, with her husband, Mac, and teenagers Izzy and Slade, are those closest to her. Doubting that Jack's killing was a random act, Poppy searches for a motive, as she also tries desperately to remember the four days immediately after Jack's funeral when she disappeared, leaving family and friends frantic, before suffering a nervous breakdown. Headstrong, she ignores advice to be wary of the sculptor she met in a bar and to disregard hallucinations of Jack warning her to let the past go. As Unger builds suspense, blurring the lines between dreams and reality, she considers how well one person can ever know another, as secrets abound. Another fine psychological thriller from a master of the genre.--Michele Leber Copyright 2018 Booklist