With Nell gone, Marcus takes control of the territory and is forced to learn how to run a business while protecting it from rival gangs. Paul Rinaldi thinks the case is closed, but he soon realizes that the operation has not stopped. He is drawn back into the world of Avon Street as he discovers that the violence in the neighborhood is escalating into a larger conflict.
Following Nell's arrest, Marcus panics about what to tell Mac and also realises he has to get back to the house and retrieve Nell's phone and money stash before Paul does. Meanwhile, Paul interrogates Nell. Nell doesn't break or say anything, but enough evidence is found to put him in jail for 5 years. Marcus manages to get Nell's phone in the house with evidence of the drug business and the money, but has to hide in a closet as Paul arrives back at Nell's house to collect the evidence. He sneaks out of a window without Paul seeing him.
Mac and Marcus finally meet. Marcus tells Mac what happened to Nell but Mac doesn't even seem to care, slightly scaring Marcus. The two discuss a deal for new property ownership. The Capo's interfere with the Deuce Seven's. Paul takes a break from work, thinking the case is over. In the last scene of the episode Mac visits Nell in prison, who asks if he's gonna get him out. Mac shakes his head silently as he slits Nell's throat, killing him. The police are left too intimidated by Mac's power in the drug business to even investigate.
Marcus, now owning Nell's territory, learns how to run the business. Reggie and Corey are sent out to meet the cook of the cocaine they have been selling; a man named Vaughn.
Paul learns that crucial evidence was stolen from Nell's house and that Nell was murdered. Enraged, he goes to Avon to try and investigate. Marcus is forced to move into war with the Deuce Seven's against the Capo's in a street. He is forced to kill someone in the battle, making him shake. At the same time, Paul stumbles onto the war zone and encounters Marcus. The two can only look at each other in silence, frozen, before Paul has to take cover from incoming gunfire and Marcus runs away from Paul, escaping in a car. Meanwhile, Reggie's mother passes away from cancer. Reggie stays beside her in her deathbed until her very last moment, unable to accept her death. For the first time in the series he cries.
Reggie argues with the only family he has at home now; his drunken father. Daniel finally begins to do drug deals for Mac, wanting to make money for his little brother Mikey. Paul tracks Avon Street, watching the neighborhood.
Mac sends Marcus on a solo mission to watch over an old associate named Arthur for a night in an isolated location. As the two wait out the night, a long, deeply personal conversation forces Marcus to confront the reality of the business. The episode ends in tragedy after Marcus receives a phone call from Mac telling him to kill Arthur. Marcus tearfully shoots Arthur in the head, following Mac's orders.
Flashbacks from the 80's and 90's show Mac's rise in the drug business. He too began with a group of his friends, aiming to get money for his sick mother's treatments, but after an ambush from a rival gang that owns all of New Jersey called the Pagano's, all of Mac's friends were killed. After, the Pagano gang made Mac their slave in the drug business for years, draining Mac's money. Mac eventually earned their trust and was left in charge of Newark, but by then his mother had already passed. It is revealed finally that his only goal is to kill the leader of the Pagano's, Sal Pagano, for taking his life away.
The Pagano's makes an aggressive move back into Avon Street, instantly elevating the stakes of the Newark war and forcing Mac to face his past. Meanwhile, Paul’s investigation takes a massive leap forward when he comes into direct contact with Vaughn, the cook, after tracking him down. Paul tries to negotiate and bring him in to the police, but Vaughn gets in his car and speeds away. Paul chases after Vaughn but loses him.
As tensions reach a boiling point, Mac’s attempt to manipulate the rival gangs backfires, drawing the Paganos, Capos, and Deuce Sevens into a direct collision course on Avon Street. Meanwhile, Paul gets ready for a final strike on Vaughn, the cook, and Marcus moves to secure the operation before the war starts fully.
Avon Street turns into a war zone as the Paganos, Capos, and Deuce Sevens engage in a chaotic shootout. During the madness, Paul tracks down and kills Vaughn, while Corey is shot and left for dead. Marcus and Reggie start to become comfortable with killing gang members in the war as Daniel considers calling the police. Desmond worries for where Marcus is. Seeking lifelong revenge, Mac attempts to assassinate Sal Pagano, but fails catastrophically, leaving Mac brutally beaten and at Sal's mercy.