The Civil War rages across the young country of America. In this tumultuous and uncertain period, Shandunka the white Paiute brave, travels to St. Louis to try and find his sister. He is a man apart from both his tribe and the white men. In his heart, he hopes that finding his sister can give him some sense of connection.

Along the way he meets Cassie Bolton, a female gunslinger and gambler. Cassie is a rebellious sort, who plays by her own rules and plays fast and loose. After Shandunka helps her out of a tough bind, Cassie proposes they work together. Shandunka agrees hoping the money they earn from the job will help him locate his sister easier. Little does he know that the job itself will be a lot more demanding than he thought. Shandunka will come face to face with a new and terrible evil. A new kind of machine gun that threatens to revolutionize warfare and turn the tide for whatever side possesses it.