Enajstletni Trevor McKinney živi sam z mamo in pogreša očeta. Pridno hodi v šolo, kjer ga učitelj Eugene Simonet spodbudi, naj najde idejo, kako bi spremenil svet. Seveda mora svojo zamisel uresničiti, zato si Trevor izmisli nekaj preprostega, a učinkovitega in začne za naključno izbrane ljudi izvajati dobra dela. V svoj načrt vplete tudi Simoneta, ki se mu zdi pravi moški za njegovo mamo. A kljub vsej dobroti Trevor spozna, da prijaznost in dobri nameni včasih nimajo najboljšega učinka.
Young Trevor McKinney, troubled by his mother's alcoholism and fears of his abusive but absent father, is caught up by an intriguing assignment from his new social studies teacher, Mr. Simonet. The assignment: think of something to change the world and put it into action. Trevor conjures the notion of paying a favor not back, but forward--repaying good deeds not with payback, but with new good deeds done to three new people. Trevor's efforts to make good on his idea bring a revolution not only in the lives of himself, his mother and his physically and emotionally scarred teacher, but in those of an ever-widening circle of people completely unknown to him.