At night, Tris leaves Tobias’ side. She knows that if another death happens, he would turn himself over to the Erudites. Tris wants to prevent this.
Tris makes her way to her old dorms where she wakes up Christina. She lies to Christina, stating that she is leaving to visit her brother who now resides with the Abnegation. She also reveals her conspiracy theory to Christina: the Abnegation were about to do something big and so the Erudite attacked to prevent it. It was a calculated attack and only Marcus knows the truth behind it. Tris asks for Christina’s help in getting the truth out of Marcus. Tris then leaves the Dauntless headquarters.
She walks a long, long way before she nervously approaches the Erudite’s compound. She feels guilt over the deaths of Will, her parents, and Marlene. It’s this guilt that drives her forward.
At the compound, she easily approaches a man behind a desk who then gets the Dauntless traitors to come over. From there, Peter escorts her to a jail-cell type room. She’s locked inside and panic sets in.