 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.