The Choice (sequel to Resurgent)

full summary

In a world where the faction system is still intact, one courageous Amity girl switches factions: to Dauntless. Amity thinks Dauntless is to violent, destructive, and carefree. Ever since one Abnegation girl switched to Dauntless, almost bringing the faction system and causing pure terror throughout the factions, Amity has had a hatred for Dauntless. One outgoing Candor boy, also makes the courageous decision to switch to Dauntless, with all the political things being said about Dauntless, not many people switch there anymore. These two transfers then have to face the harsh change from their previous lives, to the dare devil carefree life of a Dauntless. But when Larissa and Ashton meet their trainers, Tris and Four, their worlds turn even more learning their stories and learning who these people are, while still trying to survive Dauntless initiation as the outsiders. Larissa and Ashton have to fight with everything they have if they don't want to be factionless, and dodge the obstacles that come there way physically, emotionally, and mentally.