Beatrice wants to be free from the abnegation faction because it is too plain but her brother has chosen the erudite faction, leaving his family behind. So she must decide whether to stay with her family or to choose the dauntless faction. But a force outside of her directs her choice and instead of staying, she leaves. Beatrice must live somewhere else. Then she must save her family, her boyfriend and her life.
This book is my favorite book yet. Veronica makes the characters come to life. It has so many unpredictable twists. For example when Caleb makes an unexpected decision. That sort of thing keeps me interested in reading more.