- The fact that Caleb is willing to completely throw his former identity as an Abnegation, when he writes them off as selfish, right in front of his sister. It foreshadows that he's so easily swayed by Jeanine, he's willing to betray his only living family and leads her to her death. It's even worse in the movie, with Tris visibly crying when Caleb forces her to go.
Tris: (crying softly) Faction before blood, huh? Got it.
- Al's suicide.
- Will's death. For bonus points, it keeps coming back over and over again.
- Tris's parents. Both sacrifice themselves for her. Oh, it comes back over and over again, too, in case you're wondering.
- Uriah Pedrad, just Uriah Pedrad. A Perpetual Smiler Pretty Boy with plenty of friends, a loving Idiot Hero brother, and a caring mother, What Could Possibly Go Wrong? Oh, being forced to kill a bunch of innocent submissive civilians while in mind control, having his girlfriend killed and his best friend who's in love with said girlfriend die right in front of his eyes, being forced from his home, and then have a bomb blasted just to his head's side which causes a severe brain damage that ultimately leads to his death will do. And all the time, he's trying to cheer up everyone else who's as depressed and not as tolerating as he is (read: Tris and Tobias).
- The revelation that most of the faction members are genetically damaged, and the few Divergents are the ones who are normal. Tobias and Christina probably have the most reaction. Cara, too. Exemplified best with Tris' disgust after her final meeting with the Bureau Council, who yet again prove themselves to be epic Fantastic Racists.
Tris: Besides, they're already damaged.
- Tris's sacrifice. Christina screams her lungs out, with Cara only managing to give a hug while visibly crying herself. While Tobias just stands dazedly.
- "Can I be forgiven for all I've done to get here? I want to be. I can. I believe it."
- Chapter 52-54 of Allegiant. They consist of Tobias reminiscing about all the things he had done with Tris, who's now dead. Not a single one of them lasts half a page.
- Tobias's somber reflection after he comes to terms with Tris's death: "I suppose a fire that burns that bright is not meant to last."
- In Allegiant, Christina and Tris have a conversation in which they both agree that they'll always have each other, no matter what. And then, pages later, Tris dies.
- Tris killing Will and the aftermath depicted, with Tris' mother comforting her.
- The death of Tris' mother, full stop. Probably Shailene Woodley's best acting to date - try to hold in the waterworks as this heartbreaking scene unfolds.