Notoriousoutlaw Lawrence Grey has been captured near El Paso. Marshal Neilan has aproposal for him. Neilan will set Grey free if he tries to locate John Ray, aman who was last known to be living in San Vicente, Mexico. The men Neilansent previously have disappeared or quit the job. Brick Forbes of Pittsburgh isworth millions. Ray once did him a kindness. Now that Forbes is desperatelyill, he wants to leave his fortune to Ray rather than to his own relatives. Greyagrees to Neilan?s proposal and goes to San Vicente, where he promptly savesthe life of Mexican general Miguel O?Riley during a bombing attempt. Thegeneral makes inquiries and learns that the stranger who saved his life iscalled John Lawrence and that he is studying Spanish. Another American namedDickson Jarvis, employed by Forbes?s relatives, informs O?Riley that Lawrenceis actually a wanted outlaw on both sides of the border. Later, Jarvis ismurdered. Lawrence has his own audience with General O?Riley and asks him for aguide into the mountains. O?Riley sends for Oliver Slade, a man who strangelyresembles the one who killed Jarvis. This proves only the beginning of anintrigue in which Lawrence?s life is threatened continually from all sides.