Leeds, June 1913. Deputy Chief Constable Tom Harper is a busy man. He's overseeing a national suffragist pilgrimage due in Leeds that his wife Annabelle intends to join, and his daughter Mary has exciting plans of her own. Then a letter arrives from police in New York: Davey Mullen, an American gangster born in Leeds, is on his way back to the city, fleeing a bloody gang war.

Despite Tom's best efforts to keep an eye on him, Davey's arrival triggers a series of chilling events in the city. Is he responsible for the sudden surge in crime, violence and murder on Leeds's streets? Facing a mounting workload, Tom must hunt down a cold-blooded killer while also confronting danger and tragedy close to home.