In the small town of Vilsen, a serial killer is spreading fear among the residents. As the body count rises, the local police are determined to catch the criminal before more lives are lost. Meanwhile, a young detective with a troubled past finds himself at the center of the investigation, facing his darkest fears in the pursuit of justice.

At the beginning of the 2000s, Hagamannen of Umeå was one of the country's most feared serial rapist. For a period of eight years, he raped eight women resulting in one of the largest criminal investigations in Swedish history.