Wells Fargo's top detective, Clay Nash, was transporting a wounded outlaw to San Antonio when he came across the town of Saguaro Flats. Immediately he sensed that the town was hiding a sinister secret. Marshal Mace Tanner ran things with a firm hand, and was not above cold-blooded murder when it suited him. That put him and Clay at loggerheads straight away.
Clay suspected that the town was involved in the smuggling of impoverished Mexicans across the Rio Grande, where wealthy cattle barons could exploit them as cheap labor. Before he could do anything about it, however, he had to prove it.
Technically, it wasn't any of Clay's business. But he'd just helped two Mexicans, Manuel and Rosa Alvarez, to cross the big river into the United States, and he hated like hell to think that he might have inadvertently condemned them to a life of pain, misery, starvation and ultimately ... death.