Jessie Wharton is a teacher in the twenty-first century. Or at least she was. Taking her history class to visit the ruins of a historic fort in West Texas, the scorching heat turns her world upside down. Suddenly, nothing is the way it is supposed to be. She is no longer Jessie Wharton. She is Jesse Webster. She isn't a teacher. She is a private in the US army, stationed at Fort Callaghan, a completely functional outpost. And it is 1867. Worse, she isn't a she any longer.