The Divergent trilogy starts in a futuristic, distopian Chicago where the people are divided into 5 factions - Abnegation (the selfless), Erudite (the, well, erudites), Candor (the honest), Dauntless (the crazy^Wcourageous) and Amity (the nice ones). The kids can choose their faction when they are 16; the "usual" choice is to stay in the faction where you've been raised; the heroin, Tris, chooses to transfer from Abnegation to Dauntless. The first book sets up the universe, and obviously at the end of the first book, shit happens and the society explodes. In the second book, we pick the heroes in the aftermath of these events; factions are divided (both between them and internally), it's a mess, everyone's against everyone else, conspiracies everywhere, and so on. As for the first book, it's not mindblowing, but it's still a very enjoyable read.