Chicago cop Craig McHugh is working undercover to expose a heroin ring; back home, his bored wife, Leslie, is tempted by a come-on from a friend of her teenage daughter's. Meanwhile, the daughter gets nabbed possessing a small amount of drugs. Theresa Schwegel, an Edgar winner for her debut, Officer Down, weaves these three subplots together not only for quickening suspense but also to achieve something more. She creates a portrait of a family in crisis, and her vivid characterizations — stressed husband, yearning wife, floundering daughter — lift the thriller plot of Person of Interest to literary-novel status. A-