Captives is about a futuristic world where there are the Safe Cities and the people who live in the wild, the villagers. The people in the wild don't want to live in the Safe Cities, but the Safe Cities want them. The Cities are infected with a virus called Thin Plaque. This disease makes them not able to reproduce, so they need the villagers to reproduce. But the villagers must escape the cities and rebuild their villages.
This book reminds me of Reboot in the way that they cut each other off from the outside world. The villagers are always trying to prove how good they are compared to each other. They also try to fend off people who try to hurt people in their village. This book deserves to be read by all ages.