Tris Pedrad is the younger sister of Zeke, and the twin sister of Uriah.
The twins are always up to no good; doing pranks, annoying Dauntless leaders, and eating more food than is healthy for a bodybuilder.
Read as Uriahcorn, Trissypoo and Zekey Wekey (or, on special occasions, Zekey Bear) attempt to protect each other from creepers and Candor or Dauntlesses, but often fail miserably. But at least they're still good at pranks, right?
Tris and Uriah endure the most difficult but amusing times they have ever had in Dauntless, at initiation. And initiation is a long time, especially with a person as grumpy as Four as your instructor. Not only is he grumpy, but he seems to have a penchant for our heroine, for some reason.
Will the twins lighten up the dark place we call Dauntless, or fail the challenges put forward not only by their faction, but by people they would never call allies and places that would never call home?