The Strike Team's attempt to play by the book comes to an abrupt end when they discover that the Byz Latz and the One-Niners are attempting to alter the balance of power by acquiring MP5s. Meanwhile, Claudette and Dutch investigate the murders and foot severance of Armenian men by the Armenian mob, a case that draws them closer to the truth behind the money train robbery.

Vic decides to use some of the money train robbery cash during a gun-running sting operation, but after it goes awry, tension within the Strike Team begins to mount as its members attempt to rectify Vic's mistake. Meanwhile, Dutch and Claudette seek the help of a college student named Esteban who was the only survivor in the murder of two Latino gang members.

The newly arrived Decoy Squad and the Strike Team go head to head in the investigation to solve a car-jacking case. Dutch gets in over his head on an attempted murder case.

Vic struggles with Claudette's new supervision of the Strike Team. Marked bills lead Aceveda and a federal agent closer to the truth about the Armenian money-train heist in an episode with a recurring motif of people not reporting crimes against them.

When the ex-wife and child of Julien's former partner, Tommy, are murdered, Tommy becomes a suspect, prompting Julien to team up with Mackey to conduct their own investigation. Elsewhere, Shane goes undercover to catch a group attacking gay prostitutes, and Claudette and Dutch investigate a rape case against Aceveda's orders.

Vic and the Strike Team decide to take risky measures to protect themselves from being linked to the Money Train heist. Unfortunately, their plan is interrupted when one of Vic's open cases is suddenly linked to a Narco Corrido song.

An oversight puts Waylon and Trish in serious danger during an undercover job and Claudette is to blame. Meanwhile, Tommy makes a drastic decision when he realizes nobody in the Barn can help him get back on the job.

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.

Aceveda finds himself in a near fatal confrontation, and enlists Vic to help him take down the suspects in order to help service his own personal agenda. Meanwhile after losing her position of power, Claudette rejoins Dutch on the search for the cuddler rapist as they get a stunning break in the case.

During a routine bust on bangers, Vic and the Team discover a money laundering ring that reaches far and wide in the crime community. Meanwhile, Dutch takes the chilling confession of the man who was arrested in the serial-rape case, and Danny goes undercover.

When Aceveda assigns The Strike Team to serve a high risk warrant against a mob killer to service his political agenda, they find themselves embroiled in a hostile struggle with the Korean community. Now the Team must find out how to put an end to the situation before they end up casualties of a racial fued. Meanwhile, one of Vic's informants works with Danny on finding stolen chairs, while having eyes for her.

When a mole in the treasury department is discovered and the framed suspect in the Armenian money train robbery turns up missing, the Strike team race to find the suspect before their cover is blown. Meanwhile, Claudette attempts to make amends with the Decoy Squad by going undercover to help them on a case.

With an Armenian hit-man hot on their trail, the Strike team sweeps the streets of the Armenian community to find him before he finds them. After catching a break, Aceveda's suspicions grow about the Strike Team's involvement with the Money Train robbery. Meanwhile, Dutch and Claudette investigate a case that could repeal hundreds of convictions, which leaves Claudette having to choose between her conscience and her career.

When Aceveda confirms that the Strike Team is the target of an Armenian mob hit, Mackey must take matters into his own hands. Meanwhile, Whym's career is on the line when she disobeys Aceveda's orders to put a case to rest that may prove the innocence of convicted felons.