Trevor, a 7th grade boy in Las Vegas, is assigned a social studies project where he must "pay it forward" by doing good deeds for three people who must then do good deeds for three more people each, starting a chain reaction of kindness. Though Trevor doubts his success at first, the movement grows beyond his expectations, spreading across Los Angeles and other parts of America. Pay it forward shows that through faith in humanity, one small act of kindness can inspire others to pay it forward and change the world.