Eugene Simonet(KS), a social studies teacher, gives his students an assignment - to make an attempt to change the world for good. Trevor Mc Kinney(HJE), one of his 12 year old students comes across a brilliant idea. To pay a favour forward to 3 people instead of paying it back to the one who did it. The ultimate act of selflessness testing a person's conscience.

He starts with a jobless vagabond. Moves to his mother who is an abused wife. And also tries to help one of his school friends who is constantly bullied by elder kids. In the beginning it seems all his efforts are going in vain, but then news starts pouring in from across the state of people, thousands of them, who have been affected by this kid's act, as a reporter who himself has been affected by this starts tracing the chain back to its origin. Trevor ends up changing the life of everyone around him for good, even Eugene. 

But he pays for it, with the ultimate sacrifice!