Pay It Forward is a novel that centers on the lives of three individuals in Atascadero, California, a California city roughly equidistant from Los Angeles and San Francisco. Reuben, a middle school social studies teacher, has recently moved to the area. Reuben is disfigured and one of the few black people in Atascadero. The second character, Arlene, is a single mother who struggles with alcoholism and her poor taste in men, namely Ricky, her son’s father, who has disappeared and left her to make payments on an expensive, ruined truck. She is trying to raise her son, Trevor, a seemingly unremarkable adolescent boy whose only goal in life appears to be helping people.

At the beginning of the novel, Reuben gives his class an extra-credit assignment that asks his students to go out and effect change in the world. Although he has given the assignment many times, Trevor latches onto the idea, coming up with a system he calls Pay It Forward. In Trevor’s mind, he will help three people to change their lives, who will in turn help three people, until the idea grows so exponentially large it takes over the world. Trevor begins with Jerry, a homeless drug addict for whom Trevor buys food and clothes so that he can turn his life around. After getting a job, Jerry gets arrested for drugs, and Trevor believes his intervention with Jerry to be a failure. Next, Trevor sets up Reuben and his mother, as Trevor believes both are lonely and in need of company. Reuben and Arlene have a tenuous, off-and-on relationship, but end up getting engaged, which delights Trevor. Next, Trevor helps an old, arthritic widow, Mrs. Greenberg, with maintaining her garden. Greenberg dies shortly after, leaving Trevor to believe his plan a failure.

However, Trevor does not know that Mrs. Greenberg paid it forward to three other people, using her life insurance money to help out three struggling individuals. One of these individuals, Matt, then pays it forward by saving a gangster, Sidney G., from being murdered, although he does not think Sidney G. is worthy or capable of carrying on the idea. Similarly, Jerry has found his way out of jail and ends up in San Francisco, where he saves a woman named Charlotte from committing suicide. As Trevor believes his plan is falling apart, the audience is made aware that it is actually working, as they are able to read about various instances of Pay It Forward, which ultimately metastasizes into a movement, spreading throughout Los Angeles and San Francisco and eventually making its way across the country.

As Trevor believes his plan has failed, he also witnesses the failing of the romance between Reuben and Arlene. Unexpectedly, Ricky (Trevor’s no-good father) comes back and Arlene breaks off her engagement with Reuben to be with Ricky, which upsets Reuben. It takes Arlene a while to realize that Ricky has not changed, and she eventually throws him out. She and Reuben get back together for a night, but he cannot forgive her, and they do not get back together.

Around this time, a reporter in New York, Chris Chandler, gets wind of the movement and begins to chase the story down. He keeps hitting dead ends but is obsessed with the story, eventually tracing the movement’s origins back to Trevor. He interviews Trevor, who is then asked to meet the President of the United States. Arlene, Reuben, and Trevor travel to Washington, D.C. Arlene tells Reuben she is pregnant, but unsure whether the child is his or Ricky’s. Trevor, still believing that Jerry failed to Pay It Forward, attempts to stop a group of men from beating up two homosexual men. Trevor gets stabbed and ends up dying in the hospital.

In his martyrdom, Trevor becomes famous, and tens of thousands of people show up for his memorial and a candlelight vigil. These people promise to carry on the spirit of Pay It Forward, forever changing the world into a place where people are constantly performing acts of kindness for one another. At the end of the novel, Reuben and Arlene get married, but Ricky shows up again, only to learn that the child is Reuben’s. Reuben and Arlene give him money to help him get back on his feet and ask him to pay it forward in Trevor’s spirit.

The novel oscillates points of view between first and third person, as well as between the book’s characters. The book weaves together these narratives with excerpts from Trevor’s diary, along with excerpts from books Chris has written about the Pay It Forward movement. This allows the characters to speak for themselves while also maintaining the omnipotence of third-person narratives, often creating dramatic irony and leading the audience to know more than the characters. This also gives characters agency while simultaneously creating a narrative in which the reader is forced to believe in a kind of predeterminism, as though all of the characters are fulfilling their own individual destinies.

In this way, the novel becomes a polyvocal narrative. This collectivity reflects the communalism central to the story itself: the idea that by helping others who are struggling, we in turn help ourselves.