After months of hunting a cold-blooded murderer that the press has dubbed the Thorn Killer, Detective Greg Carver is shot in his own home. His trusted partner, Ruth Lake, is alone with him. Yet instead of calling for help, she's rearranged the crime scene and wiped the room clean of prints. But Carver isn't dead. Ruth is now leading the Thorn Killer investigation while Carver recuperates. She is keeping a deadly secret, and she'll cross every line--sacrificing her colleagues, her career, and maybe even her own life--to keep it from surfacing.