The film starts about ten minutes after the first one ends, with the main characters, Tris and Four plus a few others, are running for their lives through the forest at the end of the train line going out of a broken down future Chicago. Everybody in this society choses a community to live in at a certain age based on their personality and values. These communities are called factions. A few people (including Tris and Four) don't completely fit into any of the factions, but several, and are called Divergent. Divergents are ostracized from the society, so most of them hide it and try to live within a faction of their choice and not draw attention to themselves; however, because they are seen as a threat they are being hunted down and killed by the bad guy, Jeanine, played by a very blonde, pencil skirt-wearing Kate Winslet.
Our little group of outsiders finds refuge in the Amity faction, made up of farmers who value happiness and living a simple, peaceful life. They live in beautiful wooden structures among the trees, are led by a slightly-less sassy than in The Help Octavia Spencer, and are the only group not afraid to wear colors. That was really the best part of this movie: seeing the different factions more in depth. In the first movie we only saw Abnegation, who value selflessness, and Dauntless, who value bravery and strength, but here we get to see Amity, Factionless, Candor, and Erudite.
This movie was a lot more plot-driven than Divergent, which was more focused on the characters. This took away from the story because that is the whole point of this society: knowing yourself and understanding life based on how you understand yourself. It was a nice parallel that succeeded in the first movie, but not this one. Of course, the ending set up the third and final part of the series, Allegiant, which will be split into two movies (a trend started by Harry Potter and followed by series like The Hunger Games). I hope that we will see more of the happy and colorful Amity community.
(photos collected from ink361, trisandfour, fyeahtheojames, and professionalfangirls)