A school social studies assignment leads to social changes that spread from city-to-city. Assigned to come up with some idea that will improve mankind, a young boy (Haley Joel Osment) decides that if he can do three good deeds for someone and they in turn can "pay it forward" and so forth, positive changes can occur. What appears to initially be a failure, is indeed a success that is not immediately known but is traced backwards by a reporter who is a benefactor. The initial recipients of the boy are a drug addict (James Cavaziel), his badly scarred school teacher (Kevin Spacey), and his alcoholic mother (Helen Hunt). While physically and mentally scarred by past events, the teacher is not the only one bearing scars. The young boy fears his mother's fate, particularly at his brutal, alcoholic father's (Jon Bon Jovi) hands. The mother also bears scars from her childhood with a homeless, alcoholic mother (Angie Dickinson).