Based on the novel by Bonnie Nadzam, Lamb traces the self-discovery of David Lamb in the weeks following the disintegration of his marriage and the death of his father. Hoping to regain some faith in his own goodness, he turns his attention to Tommie, an awkward and unpopular eleven-year-old girl from a broken home. Lamb is convinced that he can help her avoid a destiny of apathy and emptiness, and takes Tommie for a road trip from Chicago to the Rockies, planning to initiate her into the beauty of the mountain wilderness. The journey shakes them in ways neither expects.