Allegiant

Allegiant by Veronica Roth, 526 pages

This is the final book in the Divergent series. I would not recommend it as a stand-alone. The book picks up where Insurgent left off, with Tris and Tobias on trial as traitors. Many plot twists are explained in this book, such as how the cities, with their different factions of people, got started in the first place. Tris and Tobias both find out more about their families and each other but the war between the factions and factionless wages on and Tris and Tobias would do anything to end it.