Juan Oro, raised by Yaqui Indians, was unquestionably American, though he would never know his parents or where he had come from. In a battle between the Yaqui and the Spanish, Juan is captured and befriended by Don Jose Fontana, a wealthy Spanish grandee who later sends Juan be tutored by the notorious outlaw, Matias Bordi. Juan will become the surest shot, the deadliest hand with a knife - a true master of weapons and battle. The cost? He must kill his mentor before he comes home...