Mark Nelson is a young police officer, newly assigned to the team of John Mackey - a highly-decorated and successful detective, and author of a bestselling true crime book based on his years of experience catching killers. Mackey is a legend in the force and it's a huge opportunity for Mark, who has dedicated his life to his job ever since the death of his girlfriend years before.
When a man is found burned to death in his own home, Mackey's team is thrown into an investigation that grows darker and more complex at every turn. The evidence points to a man known as the 50/50 Killer.
The 50/50 killer preys on couples.