In Among the Hidden, Haddix uses the development of Luke Garner from a frightened and powerless child into a self-aware, confident young adult to explore several important themes. Unlike Utopian and dystopian works, which describe imaginary societies, this novel concentrates on the maturation of one twelve-year-old boy as he learns about the society he lives in, the freedom he has lost, and the costs of choosing to make a difference in the world. Luke confronts the developmental tasks of all young adults, but he does so in a dystoptian world where he is not even supposed to exist.

As the story begins, Luke's mother is exhorting him to get in the house and hide immediately because the government has begun to cut down the trees next to their house that have previously hidden Luke from view when he is outside. Until he turned six years old, Luke's family sheltered him from the knowledge that he was different, and he believed that when he turned six he would be able to go out into the world like his brothers. Although he has always been the only one in his family to ask "why" questions, as he has grown up he has learned to be somewhat satisfied with his life. As a "third" child, he has always been special to his mother; she chose to keep him in defiance of the government. However, the government is cutting away more of Luke's life as it takes down the trees. Luke begins to realize that not only is he different from the rest of his family, but he is actually illegal—"There is a law against Luke." The government's actions in cutting down the woods and then forcing the sale of the family's hogs oblige Luke to stay in the house, and he becomes even more isolated as he withdraws first from his brothers and father and then from his mother. Just at the time when most adolescents begin to separate from their families by venturing out into the world, Luke separates from his by withdrawing to the attic.

Jen Talbot, who challenges gender stereotypes with her rough and tough appearance and attitude, introduces Luke to a whole new world, so much so that when he returns home, he tunes out his family. Jen prides herself on being as disobedient as possible without getting caught; she participates vigorously in an Internet chat room for hidden children and even posts antigovernment comments on government web sites. From Jen, Luke learns not only about disobedience but also about wealth, poverty, divorce, gender selection, and potato chips. Jen tells him about the history of the population laws, the corrupt and manipulative practices of the government, and gives him new books and computer printouts to read.

But Jen introduces Luke to two even more important new ideas—friendship and thinking critically about the world. When Jen deliberately cuts her hand to hide the fact of Luke's existence from her parents, Luke is amazed that she would do something like that for him when they just met. Later, when Jen seems not to be home, Luke realizes that he now has someone else to worry about other than himself. After carefully reading the books and articles that Jen gives him, Luke begins to question what the truth is since all the books and articles appear to be true, but they contradict each other. In addition, when he realizes that the Barons have lots of money and power but rarely get to eat meat while his family is dirt poor but eats well everyday, he begins to see more complexity in...