In her sixth case, police detective Marti MacAlister, a widowed mother recently engaged to a paramedic, investigates the death of a young Chicago woman found along the rocky shore of Lake Michigan in Lincoln Prairie. The woman's injuries indicate foul play, but Marti and her partner, Vik, have no strong evidence against the prime suspect, the victim's drug-dealing boyfriend. Meanwhile, a homeless man and part-time snitch named Isaac hasn't seen his buddy Dare on the street in a week, and Marti knows the missing man stayed in an abandoned building near the murder scene. What Marti doesn't know is that while she's working hard to stop one killer, another from the past has her family in his sights. Unless Marti can outsmart them both, she will lose everything she has worked so hard to protect.