A twelve-year-old boy goes missing in a traffic accident near Buenos Aires and suffers from amnesia. An elderly woman, who makes her living by collecting cardboard, takes him in and has him work for her. When she falls ill, she advises him shortly before her death to travel north, believing that his parents come from the United States. The woman's relatives help him cross the border into Chile. From there, he hitchhikes north along the Pan-American Highway. In Lima, he is kidnapped by a man and sold as labor to the owner of a gold mine. When the man dies in an explosion, he continues his journey north but is robbed and nearly killed by a truck driver in Colombia. A woman finds the injured boy and nurses him back to health. In the city of Medellin, he is taken in by a gang and becomes involved in their activities.