Below the Mogollon Rim — Alex Stoffel

The brother to the junior senator from Virginian sails to England seeking his niece, who disappeared at the same time a British military attaché abruptly leaves from his homeland. The brother finds the young girl in a morgue, beaten and badly abused. He finds the man responsible for her death and kills him in a duel. Dueling, however, is illegal in London. He is arrested, convicted on the spot, and put in chains in a ship. He is released and given the option of accompanying a British major who is given a task by the Queen to find, capture, and return alive a large, violent, treacherous Irishman who has no desire to return. The American is freed whatever the case but is only requested to assist in the Irishman's capture. He agrees to this unlikely partnership. Then saga begins.