Claudette gives Vic a chance to save his job if he agrees to train his potential replacement. An unsolved rape case from the past that Dutch and Claudette were working on resurfaces. Meanwhile, Aceveda meets someone that can help him further his political career.

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.

After Vic disowns him, Shane turns to the Armenian mob for help. Vic gets more involved with the San Marcos investigation, while Dutch and Billings are able to track down someone who survived the massacre.

Vic learns about his true status at the Barn from Hiatt. Shane gets involved with the daughter of an Armenian mob boss. Claudette begins to question Hiatt's loyalty.

As progress is being made in the San Marcos investigation, Vic receives bad news about his career. Meanwhile, Shane and Diro become business partners as she prepares to take over the Armenian mob.

Claudette notices Hiatt's mistake when he makes an arrest, and Billings delivers shocking news to the department. Vic forms an alliance with Aceveda, while he waits for his review board hearing. Meanwhile, Shane's life keeps spiraling out of control.

Vic challenges Shane and deals with threats to his family; a federal agent arrives in Farmington to investigate a recent wave of violence.

As a local gang war heats up, Vic positions himself as a valuable commodity to the warring parties; Corrine and Cassidy confront Vic.

The gang war erupts in unexpected ways that Vic cannot control; Dutch and Billings' homicide investigation grows into something more disturbing; Cassidy reaches out to Danny.

Vic sets into motion plans to end the gang threat as his relationship with Cassidy deteriorates; Dutch and Billings investigate a possible sleepwalking murderer.

A prostitute from Vic's past is the key to taking down a violent drug dealer; Dutch worries about Claudette's health; Danny takes drastic measures to protect her child.

A local priest may be protecting drug dealers; Dutch and Billings close in on attempted cop killers; Corrine learns uncomfortable truths about Vic.

Vic closes in on Shane, Mara and their sick young son; Claudette dismantles the Strike Team; Pezuela offers Acevada "assistance" for his mayoral campaign; Rita Denton (Frances Fisher) comes on to Dutch; and Billings' ex-wife and daughter are fearful when a registered sex offender moves into their neighborhood.

While Shane remains holed up in L.A. with Mara and Jackson, Corinne decides to cooperate with Dutch and Claudette, who's now spearheading the LAPD effort to bring down Vic. Meanwhile, Vic plays Aceveda, Pezuela, Beltran and ICE against each other. But Ronnie's tempted to simply give up and run to Mexico. "And you should run too man" he tells Vic.