Stephen Doyle, an Irish-American veteran of the Civil War, arrives in Manchester from New York with a thirst for blood. He has joined the Fenians, a secret society intent on ending British rule in Ireland by any means necessary. Head Constable James O'Connor has fled grief and drink in Dublin for a sober start in Manchester, and connections with his fellow Irishmen are proving to be particularly advantageous in spying on Fenian activity