In 1871, 12-year-old Billy McCarty and his immigrant Irish family have to leave New York and travel west to seek new opportunities; but the journey proves fatal for some.

Kathleen and her sons Billy and Joe travel on to Santa Fe; life is hard, but she meets and marries a man who might change everything for the better - only to find that he makes it a lot worse.

Antrim, Kathleen and the two boys relocate to Silver City, trying to start a new life; but all their dreams are shattered - and Billy loses everything.

Billy finds fresh trouble when he falls in with a character called Alias; he kills a man in self-defense and ends up on the run, and then in the arms of a young woman - who also happens to be the girlfriend of Jesse Evans.

Billy, on the move again, ends up in Chihuahua, Mexico, with a new Mexican friend called Segura; together they enjoy several risky escapades -- but in the end, Billy risks losing his life.

Billy bumps into a new character called Pat Garrett, who is riding with Jesse and the 7 Rivers Gang; Billy joins them - but law makers are already closing in; they plan to flee to Lincoln County - but not before Billy fulfils one last promise.