Following The Son, the fourth novella in Veronica Roth's Divergent series, The Traitor, is probably the best of the series’ first four novellas. This story is set during Tris' initiation, so a lot is unfolding, and we get to see Four's perceptions of and reactions to Tris. What was most interesting about this novella was the relationships it revealed; Four's relationship with Dauntless leaders, his semi-realignment with Evelyn, and his attempt to warn Marcus. I was also surprised to find out how long Four had known about the serum and Erudite's plan and frustrated that he couldn't put the pieces together.
Additionally, this story added depth to Four's character by sharing his thoughts during interactions with Eric and Max; whenever he spoke to them, it was always calculated; he was always working with intent. Four's values were continuously fortified by his reaction to Al's death and how he dealt with Peter.