After P. C. Gordon is murdered and robbed of a diamond ring that he bought as a birthday present for his wife, one of the thieves, C. Dates, is apprehended. A woman prosecuting attorney makes a compelling case against him, and he is given a ten-year penitentiary sentence.
It's just after the Civil War and Captain Morgan and his confederate soldiers are establishing a town on the Bozeman trail. Colonel Strong and his union men are at the nearby fort. Things are peaceful until Riley has the Indians attack a union wagon train and leave a confederate sword at the scene.
