The debut novel from Veronica Roth, Divergent imagines a future after a generic great war. The only way to restore peace is to divide humanity up into 5 Death Frats named after SAT words. People join them by having only one personality trait: brave people join Dauntless where they jump off trains and punch each other. Smart people join Erudite where they... wear glasses. Amish people join Abnegation where they don't eat hamburgers. And the other two are both Hufflepuff.
In the EXTREMELY RARE situation where somebody has two personality traits ("I have glasses AND I'm a vegetarian!" -or- "I play baseball AND football.") they are "divergent" (a Latin word meaning "too cool for school." Bo knows divergence.)
"But wait," you say. "How do they figure out which frat to join?" I'm glad you asked. Pledge week in Dystopian Chicago consists of a hallucination where you have to choose between a knife and cheese with no other instructions. Then a dog attacks you. If you choose the knife, you are Dauntless. If you choose the cheese, you're not. Isn't that cool? That's all it takes to determine your whole future. You either want a knife or you want cheese, and that decision confines you to a single Death Frat for the rest of your life. What if I'm not selfless, I'm just lactose intolerant? SHUT UP YOU'RE DIVERGENT.
Eventually the smart people use the brave people to kill the Amish people (because REASONS!) and only a teenage girl with two different interests can save them all. With her boyfriend. And something about a hard drive that controls humanity (presumably connecting via USB 27.0).
It doesn't make much sense, but I can't wait for the movie for one reason: in the book, there's a zip line from the top of John Hancock tower.