Luke is a 12-year-old boy who lives secretly in the attic of his family's farm, as he is an illegal third child in a world where the Population Police enforce a two-child policy. He discovers that another third child, Jen, lives nearby and they meet in secret. Jen hatches a plan for third children to rally at the White House to protest the population law. However, the rally is a trap set by the Population Police and all the children, including Jen, are killed. Luke is then forced to leave his family behind and assume a new identity to avoid being caught himself.