Everything you need to understand or teach Among the Enemy by Margaret Peterson Haddix.
Matthias, Percy, and Alia are three friends living at the Neidler School. The country has experienced a severe shortage of food and all families are banned from having more than two children. Third children are illegal and, if captured by the Population Police, are killed. Matthias, Percy, and Alia are all third children living with fake identity papers. They are roused out of their beds one night by the Population Police...