The seventh (and final) season begins with Vic challenging Shane and dealing with threats to his family. Meanwhile, a federal agent arrives in Farmington to investigate a recent wave of violence.
The Mexican-Armenian gang war heats up, enabling Vic to position himself as a valuable commodity to both sides. Meanwhile, black-on-white violence hits Farmington; Corrine and Cassidy confront Vic; Billings returns to work; and an Anglo rock singer is killed when someone in the predominately Hispanic apartment building where she lived drops a concrete block on her head.
Corrine finds herself in legal trouble; Vic works an angle to make himself valuable to the Armenian mob; Tina targets a producer of adult entertainment.
Following a fire at the Armenian safe house that killed two of his lieutenants, Rezian asks Vic to set up a meeting with the Mexicans, who think (thanks to Vic) that the Armenians have Pezuela's blackmail box. Meanwhile, an angry Cassidy goes to Danny with questions about her father; and Dutch questions a teenager who shot an intruder, who turns out to be the youth's classmate. Rita: Frances Farmer.
When the daughter of a drug kingpin is kidnapped, the Strike Team must free her without drawing attention to the fact that Agent Olivia Murray (Laurie Holden) is following him. Meanwhile, serial killer Kleavon Gardner, soon to go on trial and defending himself, hits a nerve when he deposes Claudette; Dutch continues his effort to unmask teenager Lloyd as a potential serial killer; Danny pressures Vic to sign away his parental rights to their child; and Shane tries to turn Ronnie against Vic.
Vic and Ronnie set up a Mexican-Armenian meeting but tell the two sides different things and keep some pertinent details from Shane; Shane and former Strike Team adversary Tavon Garris (Brian White) team up uneasily as a six-year-old murder case heats up; Ronnie gets a warning from Claudette about Vic's freelancing; and a naked sleepwalker (Scott Michael Campbell) is found in a warehouse with blood on his body that isn't his own.
Vic's review-board hearing is moved up unexpectedly (but the result isn't unexpected), putting new pressure on his mission to take down Pezuela---which hits another snag when the Feds take over the investigation of Robert Martin's murder. Meanwhile, Vic ramps up his quest to stay in his infant son's life; Shane tends to private business as he probes a prostitute's murder; and Dutch is disturbed by what he finds at Claudette's house when he and Billings investigate a neighborhood break-in.
Vic and Ronnie escape attempts on their lives, and when Ronnie's assailant is caught, Shane must think and act quickly. Meanwhile, with barely a week to go before he must turn in his badge, Vic makes Agent Murray a business proposition. He also has some dirty work to do for Pezuela, involving a priest (Silas Weir Mitchell), whose church is in a location Pezuela finds inconvenient.
Vic closes in on Shane, Mara and their sick young son; Claudette dismantles the Strike Team; Pezuela offers Aceveda "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.
Corinne agrees to be Vic and Shane's go-between---and also agrees to cooperate with Claudette and Dutch as she does so. Meanwhile, Vic comes to an understanding with Aceveda and seeks one out with Olivia; and Claudette assigns Ronnie to work with Julian to investigate the murder of a high-school football star, keeping Ronnie out of the Barn---and unable to intercept the letter Shane sent to Claudette detailing the Strike Force's "sins."
Olivia joins forces with Vic and Ronnie to intercept Beltran's drug shipment; Dutch cleans up another Billings mess; and Mara creates a mess of her own when she rescues Shane from a perilous situation. Rita Denton: Frances Fisher.
In the series finale, cops in the Barn investigate a woman's disappearance and the arrival of a large drug shipment.