Girl, Trapped (Ella Dark, #8)

FBI Agent Ella Dark has studied serial killers from the time she could read, devastated by the murder of her own sister, and has gained an encyclopedic knowledge of murderers. But when Ella investigates a murder and realizes this is no ordinary dead body, she is at a loss: it’s pieced together with parts of multiple victims. How many people has this killer killed? And can Ella discover who did this—and why—before time runs out?