Callaghen’s business is soldiering. For twenty years he’d fought all over the world, from China to the deserts of California; now he’s a private in the U.S. Cavalry, poorly paid, his enlistment about to run out. He’s ready to move on . . . until he comes across a startling discovery: a treasure map belonging to a dead lieutenant who may not have been all that he seemed. The map points the way to an underground river of gold . . . or does it? To find out, Callaghen will have to fight the toughest war of his life: against a fierce Indian warrior, a vindictive commanding officer, and a ruthless gang of outlaws who’ll turn what may be a river of gold into a river of blood.