Recker's time away is cut short when tragedy hits the team. He comes back to find that someone is targeting them. The question is who? Is it a new enemy that they have to deal with? Or is it someone from their past, who has regrouped to try and get revenge for their prior skirmishes?

Thrower is hired by Logan Yarbrough, who is the agent for model Monica St. James. She has been receiving threats, but she's also scheduled to leave the country to go on some photo shoots across Europe. While Thrower and St. James don't mix well at first, they soon develop an affection for each other. While in Europe, they're in almost constant danger. And in order to get out of this, he's going to have to figure out who's behind the threats on St. James' life. Once he does, the answer is surprising, and not what he suspected. But he'll do what it takes to protect his client and take the fight to his enemies, no matter what it takes.

Nate Thrower is in Mexico, barely finished with one job when another one literally shows up at his doorstep. He's hired by Manuel Ortiz, a wealthy CEO who's been receiving threats. The threats soon escalate into violence, with everyone in Ortiz' family now directly in danger. People are getting hurt. With things spiraling out of control, Thrower makes a call to an old friend to help him out of the jam. Together, they'll Silence their opponents and eliminate the threat.

Somebody is shooting police officers. After several killings, and no progress on finding the shooter by the police department, Recker is asked to lend a hand. One of Vincent's men inside the department, a homicide detective, reaches out to The Silencer, setting up a meeting through Vincent. As Recker, Haley, and Jones investigate the killings, they start to find more questions than answers, and realize that everything is not as cut and dried as it seems.Once the supposed killer is finally found, Recker thinks he may have been played. He's not so sure that it wasn't a plant and the man was framed. All of which leads him to question, if it's someone else behind the shootings, who has the power and motivation to pull it off? And why?

After getting back from London, Recker and the team are immediately swept up in Vincent and Nowak's feud again. Though they initially refuse in getting involved, their minds are changed when they start getting ambushed. Recker is ambushed in an alley while trying to prevent a jewelry store heist, Haley has his car blown up in trying to track down the suspects, and Tyrell's relationship with Recker is found out, leaving him in a vulnerable position. The team learns it's all part of Nowak's plan to rid the city of all of them, leading them into an eventual final confrontation with her. One that will be deadly.

Another menacing force has entered the city. The Tri-State Scorpions have migrated from New Jersey and are looking to make the city their own. Recker and the team have plans to stop them, but it will come at a cost. After one of the leaders of the Scorpions gets in a shootout with Haley, he is transported to a local hospital that Mia is working at. The Scorpions take over the hospital, causing it to go on lockdown. After receiving a troublesome text message that indicates Mia is in some type of danger, Recker must find a way to get into the hospital and save her... before it's too late.

There's a new criminal element in town and they state their arrival by knocking off a few of Vincent's men. Recker and the team get drawn into the middle of it and start investigating to learn the identity of the mystery player. Recker and Haley get a tip about a high-level meeting of the new crew in an abandoned building, but all is not what it seems. Instead of a meeting, they run into Malloy, who's also there to investigate, and an otherwise empty building. It turns out to be an ambush, and only two of the three will escape uninjured.Will they find out who's responsible for the attack and bring them to their brand of justice? Or will the perpetrators slip out from under their fingers to cause more chaos and destruction?

Jones finally has his number called. Someone from his past is gunning for him. What's really worrisome is that whoever it is, might have skills that even surpass Jones'. After finding out that their secret office isn't as secretive as they thought, the team has to assume that they're being watched, and listened to, at all times.Recker will have to call on old friends, and some new ones, in order to help find the identity of the person who's after his friend and partner. Can he accomplish that before Jones is eliminated?