Burgess gives chase after Roman is wounded by a hooded perp who opened fire on their patrol car and shoots who she thinks is the suspect, but no gun is found at the scene—and the person she shot is a 17-year-old honor student.

In the Season 3 finale, the team investigates the murder of a single mom who was in contact with Voight's now-reformed son, who was himself brutally assaulted. Meanwhile, Roman makes a major decision and Crowley plans to make changes within the unit.

The team investigates a murder in which the victim appears to have been wearing a CPD-issued wire. Burgess works a case with a new partner. Crowley questions Lindsay about the night that Intelligence pursued Justin's killer.

Platt is sent to the hospital after a vicious attack outside her father's house. Mouch is questioned and past threats against her are revisited while the team investigates. A gruesome discovery inside the father's home ups the ante in the case.

A car plows through a crowd outside of a concert venue and is followed by gunfire, sparking fears that it may be terror-related. Burgess spots Atwater's brother where he shouldn't be. The team works to bring peace to the community before more blood is shed.