| Director | Mimi Leder |
|---|---|
| Genre | drama film, film based on a novel |
| Runtime | 123 min |
| Country | United States |
| Budget | $40 million |
| Box office | $55.7 million |
Trevor McKinney begins the seventh grade in Las Vegas. His social studies teacher, Eugene Simonet, assigns the class to put into action a plan that will change the world for the better. Trevor calls his plan "pay it forward", which means the recipient of a favor does a favor for three others rather than paying it back. However, it needs to be a favor the recipient cannot complete themselves. Trevor implements the plan himself, forming a branch of good deeds. His first deed is to let a homeless man named Jerry live in his garage, and Jerry pays the favor forward by doing car repairs for Trevor's mother, Arlene, though Jerry later disappoints Trevor by moving out and returning to drug use.
Meanwhile, Arlene confronts Eugene about Trevor's project after discovering Jerry in their house. Trevor then selects Eugene as his next "pay it forward" target and tricks Eugene and Arlene into a romantic dinner date. This also appears to fail, and Trevor and Arlene argue about her love for Ricky, her alcoholic ex-husband, to the point where Arlene slaps Trevor in a fit of anger. Eugene and Arlene are brought together again when Trevor runs away from home.
Trevor's school assignment marks the beginning of the story's chronology, but the opening scene in the film shows one of the later favors in the "pay it forward" tree, in which a man gives a car to Los Angeles journalist Chris Chandler. As the film proceeds, Chris traces the chain of favors back to its origin as Trevor's school project. After her date with Eugene, Arlene pays Jerry's favor forward by forgiving her own mother, Grace, for her mistakes in raising Arlene, and Grace, who is homeless, helps a gang member escape from the police. The gang member then saves an asthmatic girl's life in a hospital, and the girl's father gives Chris his new car.
Chris finally identifies Trevor as the originator of "pay it forward" and conducts a recorded interview in which Trevor describes his hopes and concerns for the project. Eugene, hearing Trevor, realizes that he and Arlene should be together. As Eugene and Arlene reconcile with an embrace, Trevor notices his friend Adam being bullied. He pays forward to Adam by rushing into the scene and fighting the bullies while Eugene and Arlene rush to stop him. One of the bullies pulls out a switchblade as another one pushes Trevor against him, stabbing Trevor in the stomach. Trevor later dies from the stab wound at a hospital.
Trevor's death and the spreading "Pay It Forward" movement are then reported in the news. The movie ends with Arlene and Eugene mourning Trevor's death at Arlene's home when they see thousands of people affected by the "Pay It Forward" movement, including students from Trevor's school, gathering outside in a vigil in Trevor's honor.