This book is about a girl named Ava and her little brother Lucas, who are sold to the army, but this army isn't like the others. This army is a top secret army the government made for the unwanted. You could be a Fighter, Slave, or a Medic. They replace your name with numbers and once they reach a certain number they will go and fight Not Humans but creatures that have been thought to have gone extinct. That all I gotta say. Read if you want.