Six months ago, a case nearly cost Sophie her life. So when a detective friend asks her to visit Arizona, she welcomes the break. But her vacation ends abruptly when bodies are found at a university and she gets pulled into the case. The horrifying methodology—deliberate body positioning, a distinctive red heart scrawled on each victim—indicates to Sophie that a new serial killer has claimed the area. Oddly, though, certain signature elements differ between killings. Fortunately, the FBI database has a record of many of the signatures—but each belongs to a different serial killer.

As the bodies continue to appear, Sophie must hone her terrifying skills and suffer the horrors in her head in order to stop this killer.