Alvaro Nuñez has crossed the border many times, but this time is different: his son Omar is coming with him to live and work in the U.S. For Danny Jackson the Arizona borderland is home, although since his mother left he has been struggling to adjust to life there with his father Luke. The Line follows these fathers and sons as they attempt to rebuild their relationships under new circumstances, an endeavor made even more important by the high stakes of life at the border. When their paths cross, each person, and each family, is changed forever.