The movie is about a 12-year-old boy named Trevor McKinney (Haley Joel Osment) who wants to make a difference in the world. He comes up with a plan called "Pay It Forward," where he does a good deed for three people and asks them to do the same for three other people, and so on.
One of the people Trevor helps is a former drug addict named Eugene Simonet (Kevin Spacey), who is burned severely when his alcoholic father pours gasoline on him and sets him on fire. Trevor helps Eugene get back on his feet, and Eugene eventually becomes a teacher.