A 17-year-old inmate is raped and killed in prison. As Katrine Ries Jensen goes up against the system that has made the attack possible, she is forced to confront a past she would rather forget. When yet another prisoner is killed in the same manner, it swiftly becomes clear that this is not just a sex killing. A serial killer is at large in the prison. The case attracts widespread public attention, and the police come in for heavy criticism. Under intense pressure, Katrine and Thomas Schaeffer struggle to track down the perpetrator in a place where violence and revenge are rife. A place that gets under both their skins, and brings out sides of them they would prefer not to acknowledge.