A small town called Longbill Beach hides the mystery of Emily Von’s murder. In 1982, a seventeen-year-old girl is preparing for prom, but she has a secret that becomes the reason for her death that night. Forty years later, the murder remains unsolved, but federal marshal Andrea Oliver comes to town to unravel the riddle. The investigation leads her to other mysterious deaths, and she realizes the killer is still on the loose.