Tris, Tobias, Peter, Caleb, and Marcus are seeking refuge in Amity after having successfully stopped a simulation that controlled the Dauntless and made them kill innocent members of the Abnegation faction. This story takes place in futuristic Chicago.
I killed Will.
Once in Amity, Johanna Reyes, Amity's representative, lets them stay as long as there is no conflict, but Tris and Peter get into a fight and all of them are forced to leave. Tris decides to cut her hair chin-length during her time at Amity.
I chose Dauntless to escape my father
Before leaving Amity, Tris overhears a conversation between Marcus and Johanna which leads to Marcus telling Tris that Jeanine made the Dauntless attack Abnegation in order to steal essential information from them.
After leaving Amity, Tobias and Tris encounter Tobias's mother, Evelyn, among a group of factionless on a train. She was thought to have died years ago, but far from being dead, she has plans to usurp Erudite and demolish the faction system. Tobias resents her for leaving him to live with his father while he was being beat by him.
Once off the train, Tris and Tobias arrive at Candor. They are arrested upon arrival and are put under a truth serum. Tobias confesses he chose Dauntless to escape his father, and Tris confesses having killed Will, one of her best friends who was under the attack simulation, in self defence. She confesses this in front of her best friend and his ex-girlfriend, Christina.
Dauntless traitors that supported the Erudite attack on Abnegation invaded Candor headquarters. They killed a twelve-year-old Divergent, but Tris stabbed Eric, one of the perpetrators of the attack, before he could kill any more innocent people. In the attack, most people were injected with a serum that was capable of controlling everybody but the Divergent.