The start of this book continued right were the last one left off. The factionless have taken over, and things are looking bleak for Tris who has been imprisoned once again for treason. Oh did I mention that Tris and Marcus found a recording of someone from a long time ago who told them that basically their life is a lie, and something needs to be done about the happenings going on outside the fence, and nothing that they know is actually true. Yep, that happened. Of course curiosity gets a hold of Tris, and she has to know what is going on outside of the fence, which people have been telling her her whole life is dangerous, but they don’t know why. Also on the rise are a group of people who are becoming rebels to Four’s mom being in charge, and they are calling themselves the Allegiant, and they would like for Tris to help them. Tris decides that the Allegiant should be helped, and they make a plan to get outside of the city and on the other side of the fence. What they find there is something none of them would ever expect.
Just when you think things won’t get any worse of course they do. Tris, Four, Caleb, Peter, and Marcus are able to make it out of Dauntless and Abnegation. With the leaders of Abnegation now dead, and the Dauntless brainwashed to kill others on command the safest place for them to go is Amity. Of course instead of things getting better Amity is now attacked in order to find the remaining members of Abnegation. The group barely makes it out of there, and on to an oncoming train, which reveals members of the Factionless including some old acquaintances, and some surprises as well. It turns out the Factionless aren’t as down trodden as people like to assume, and they have been making plans for this moment as well. The Divergents are being discovered and slowly being taken out and questioned in order to make a more potent serum.