After killing a man in self-defence in Ireland, Molly Murphy flees the country by taking another woman’s place aboard a ship to New York. Her arrival at Ellis Island appears to offer a new life until a man with whom she argued is found murdered and the authorities treat her as the principal suspect.
Molly escapes into Manhattan and begins investigating the victim and their fellow immigrants. While avoiding arrest and the danger she left in Ireland, she searches Hell’s Kitchen and the Lower East Side for the evidence that will clear her name.