I read this first-of-a-trilogy for the book club. Although the book owes large debts to both The Hunger Games and Harry Potter series, the author HAS created a unique universe, so props to her.
Sometime in the not-too-distant future, society is arranged not by class, color, or sex, but in factions according to a primary characteristic: Erudite (reason/intelligence), Amity (peace/love), Dauntless (courage/braveness), Candor (honesty), and Abnegation (selflessness). People choose a faction on their 16th birthday, after undergoing testing to see which would be most appropriate. People who don't have a clear result, like our heroine Beatrice (Tris), are called "divergent," and they represent a threat to the prevailing order.
It's hard to judge each component of a series until the whole thing is finished, so for now, let me just say that this is a quick read, with lots of action, a couple of twists, and hints of things still to come. I enjoyed it.