The futuristic film opens with Naomi Watts' character, Evelyn, now in charge of walled-in Chicago after the demise of Jeanine, and she's trying to provide 'justice' for past sins against the members of Erudite by conducting public trials in which they're put to death at the whim of angry mobs.  Those who think that Evelyn is merely a replacement for Jeanine in Machiavellian tactics splinter off into their own group, the Allegiant, led by Johanna (Spencer), and civil war is about to break out for control of the city.  Meanwhile, Tris and her cohort of rebellious heroes manage to scale the walls of the city to try to find something or someone that will remedy the situation on the outside, eventually leading to an encounter with the Bureau of Genetic Welfare, led by David (Daniels), who instructs Tris that their entire existence has served as an experiment for the last 200 years in trying to purify the damaged genetics of humanity, and that Tris' purity as a Divergent means that the experiment is a success.  However, with Tris' home and nearly everyone she cares about about to kill each other, and an organization that's supposed to be looking out for their well-being showing that they might not be the benevolent rescuers she is hoping for, she's going to have to take matters into her own hands if she wants to fulfill that role of savior of humanity she's been destined to be since birth.