"Among the Enemy" is the sixth book in Margaret Peterson Haddix's "Shadow Children" series. It's a young adult dystopian novel set in a future society where third children are illegal due to overpopulation laws. The story follows Luke Garner, a third child who has grown up in hiding, as he becomes involved in the resistance against the oppressive government known as the Population Police. In "Among the Enemy," Luke finds himself in a position of leadership within the resistance as he navigates the dangers of the authoritarian regime and struggles to protect himself and his friends. The series as a whole explores themes of freedom, identity, and the consequences of societal control.