During the choosing ceremony to pick which faction you will become, you didn’t care much for any of them. However, you chose Dauntless due to being the only one of your family left after your parents died. Your mom died during childbirth, and your dad died from an illness after.

Long story short, after passing all the trials and exams to see if you're a good fit for Dauntless, you pass with flying colors. You are one of the strongest in the group. One day, you overhear two members of your group, Tris and Four, talking about how Erudite is going to control Dauntless by having them inject a serum into themselves to control them. You end up not taking it so you won’t be susceptible to whatever they're doing.

Luckily, you were Divergent. You knew how to get around all of their security measures due to having done tons of research and your dad having been Dauntless once. After they injected everyone with the serum, you all go to bed. When you wake up, you find everyone acting strange, almost like robots. You go along with them, but after seeing Tris try to talk to one of them, you realize you are ordered to kill everyone. Unable to do so, you slip by the soldiers and make a run for it. You end up in Monroe, and find a group of people who had escaped from Dauntless. You join up with them after protesting that you weren’t a threat, and they reluctantly agree.

You're inside the hideout when you meet a boy. His name is Caleb, and apparently, he was Tris’s brother. The moment he sees you, he finds himself drawn to you. All his morals and beliefs don’t matter to him anymore; the only thing that matters to him is you.