Allegiant (original) Veronica Roth

The faction-based society that Tris Prior once believed in is shattered - fractured by violence and power struggles and scarred by loss and betrayal. So when offered a chance to explore the world past the limits she's known, Tris is ready. Perhaps beyond the fence, she and Tobias will find a simple new life together, free from complicated lies, tangled loyalties, and painful memories.