Matthew was raised by a profoundly religious Mexican mother and Anglo father. In his 20s, he believes he has been called by God to embark on a mission to spread the gospel among the indigenous Tarahumaras in northern Chihuahua, Mexico. He leaves behind his family and sweetheart to walk "like Jesus walked." He also hitchhikes through the remote southern New Mexico desert and the rugged Sierra Madre into the Copper Canyon area. Matthew befriends Jesús and stays with his family, working with him in the field by day and engaging in long conversations at night. They discuss folk beliefs, the Tarahumara religion, and philosophy. Matthew's faith begins to waver and he finds himself in a sea of ambiguity. Following a dramatic change of mind, heart, and soul, on his way home he has a run-in with drug traffickers and kills one of them; he is mugged twice and loses his faith in the goodness of mankind; his financial resources diminish, compelling him to collaborate in a robbery. In short, his life becomes what before his journey would have been virtually unthinkable.