Shane's guilt for killing Lem intensifies after the Strike Team learns that he didn't make a deal with the authorities, and Kavanaugh resorts to threatening informants and planting evidence to pin Lem's murder on Vic.
Detectives discover the evidence Kavanaugh planted to make Vic look guilty for Lem's death, but Dutch begins to suspect that everything is too convenient. Meanwhile, Vic tries to find the Salvadoran leader Guardo, who escaped to Mexico.
Vic captures Guardo and tries to coerce a confession to Lem's murder out of him. However, Shane, the real killer, begs Vic for leniency on Guardo's behalf. Meanwhile, Dutch and Gardocki bring down a gang of meth dealers.
Claudette begins making radical changes to the Strike Team in anticipation of Vic's imminent forced retirement. Meanwhile, Vic's helplessness for not saving Lem boils over after he fails to play peacemaker in a gang war.
Shane is hospitalized after a beating, and his wife leaves him for having an affair. An unlikely suspect emerges in the serial rapist case, and an undercover agent in the Salvadoran gang tells Vic that Guardo didn't kill Lem.
After Vic learns that Guardo wasn't Lem's killer, he begins to suspect that Shane could have been responsible. Meanwhile, Vic does a favor for a city official, hoping it will give him an ally in his quest to avoid early retirement.
Shane contacts the Armenian mob and collects information against the Strike Team, in order to protect himself from Vic. Meanwhile, Vic learns that Hernan lied about the San Marcos massacre when the Byz Lats retaliate against the Salvadorans.
Shane offers his services to Kesakhian's daughter, who is running the Armenian mob for her sick father. Meanwhile, Hiatt tells Vic that Claudette has made sure that Vic's "retirement" from the Strike Team is a done deal.
Vic's city official can't help him out with his forced retirement, but he finds a new ally when he solves the San Marcos murders. Shane and Vic fight over Kesakhian's daughter's loyalties, and Billings gets revenge on Dutch.