As a serial killer targets prostitutes in Southern California, a troubled traffic cop picks up the trail in this thrilling prequel to The Girl on the Bus.When traffic cop Leighton Jones is called to sort out an altercation in a used car lot, he is confronted by a prostitute rambling on about a girl who stole her coat. He thinks nothing of it-until the body of a Jane Doe shows up, matching the prostitute’s description. Could there be a link between the fight in the car lot and the dead woman?Leighton proceeds to gather evidence. But when he brings his findings to the lead Homicide detective, he’s told to back off. A suspect has been arrested. Yet the case is far from closed. And as Leighton keeps digging, he finds himself on the trail of a serial killer . . .