The Strike team's attempt to play by the book comes to an abrupt end when they discover that two gangs, the Byz Latz and the One-Niners are attempting to alter the balance of power by acquring MP5s. Claudette and Dutch investigate the murders and feet decapitation of 4 Armenian men by the Armenian mob in their search for the stolen cash from the money train. Meanwhile, Danny who is doing temp work at a high school while waiting for an appeal, discovers she might me be able to get her old job back.

Tension within the group begins to mount as the Strike Team attempt to rectify a mistake Vic made when he decided to use some of the cash from the stolen money train during a botched gun-running sting. Meanwhile, Dutch and Claudette seek the help of a college honor student named Esteban who was the only survivor in the murder of two latin gang members, one of them being his close friend.

A prostitute seeks the help of the police in her quest to bring down her pimp. Claudette assigns Vic against his wishes to the case, which puts him on the verge of going over the edge. Dutch uncovers a disturbing trend of rapes and a politician is arrested for solicitation.

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 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.