When two high profile murders are linked to each other, Aceveda orders Wyms to get the entire Barn involved before gang and racial violence breaks out. Mackey uses the case to leverage himself and the Strike Team back into the streets of Farmington.

As the Strike Team is preoccupied with gang violence, Kavanaugh decides to make the Barn his base of operations. An evasive serial killer from Dutch and Claudette’s past reenters their life. Meanwhile, additional strain is placed on their working relationship when Tina learns something personal about Julien.

After being badly beaten, Shane's life spirals even more out of control as his guilt continues to eat away at him and his marriage begins to fall apart. Vic and Ronnie try to learn who was responsible for Shane's attack. Meanwhile, under the new leadership of Kevin Hiatt, Claudette assigns the Strike Team to investigate the San Marcos murders. Dutch and Billings make progress in a serial rapist case.

Claudette encounters a murderous old nemesis; Vic confronts Olivia about her political connections; Dutch's case gets personal.