While on vacation with Deborah in Alexandria Bay, NY, Boone receives a call from Detective Alexandra Burton of the NYSP Bureau of Criminal Investigations. Alex tells Boone they believe the body of Shirley Anne Mosher, a seventeen-year-old girl who disappeared without a trace over thirty years ago, when Boone was a new trooper in the State Police, has been discovered. Detective Burton asks. for his help in dusting off the old file to find Shirley Anne's killer. Boone agrees to help, feeling remiss over treating the initial investigation as a runaway. The existence of two similar cases in nearby counties raises the possibility of a serial killer. Marianne, working remotely for the most part, is eager to assist, and soon finds herself in the most challenging online research in her time with the agency. The investigations move forward in fits and starts, not uncommon with cold cases of this vintage. But eventually, with Marianne's and Boone's efforts, and evidence uncovered by the New York State Crime Lab, it becomes obvious that the killer is a member of a local family in the lakeside village of Maryville, where Shirley Anne's body first went missing. But as the investigation proceeds, the only known living relatives of the killer's family die in mysterious ways. But without a name or even a suggestion of a location, the question remains. How to bring the killer to justice?