Dominic finds Vincent in the snow beside Paulie's body and gets him out before Boston's men reach the building. Boston sends crews into Newark overnight, and by morning the streets are a war zone. All of the people from Suite Osumanthus are killed. Roark is shot in her car outside her office. Holt is killed at a parking garage off Route 1. Crowley is found in his church before dawn. Elena and Maria steal a car mid-pursuit, pick up a live Boston frequency on the radio, and relay strike coordinates to Carla, who runs the Bellotti response from Tony's old back office while Dominic moves men through the docks. The fighting collapses toward the bar, where Sean arrives with his last crew and finds Vincent waiting. The room gets destroyed before Sean is put on the floor and forced to sign Newark's operations over to the Bellottis. Vincent tells him to drive north. Inside Sean's bag, Carla finds the original Mendoza sniper contract bearing Paulie's name, which begins clearing Mick.

Mick's new lawyer files an emergency appeal using the sniper contract. The conviction is overturned, and Mick walks out of jail. Ray Cifarelli moves into a formal role inside the operation and starts rebuilding contacts that Boston had cut off. Vincent partners with a Newark drug dealer named Curtis Lyle, who is an even-tempered sociopath. Elena and Maria reach a motel outside Trenton and begin uploading the Crowley evidence to journalists. Federal agents locate them and breach the room before the upload completes. Maria stays at the laptop until it finishes and is shot. She dies after the transfer goes through. Elena walks out into the road, devastated, and is taken into federal custody. She is not charged. She is offered a position inside the organized crime task force. Rudy drives Vermont back roads for days and stops at a bar, where a retired man named Gerald sits beside him and talks about memory and guilt, unaware of Rudy's life. Rudy drives away in the dark.

Elena accepts the federal position and is embedded inside the organized crime task force, where she pulls the active Bellotti file. Curtis Lyle's crew steals a shipment and then tries to assassinate Vincent late at night, but fails. Vincent escapes. Vincent and Dominic trace Curtis’ crew back to Sean, who coordinated it from Boston and has been working with them the whole time. The Bellottis hit back and recover the shipment, but Curtis escapes, and his gang stays armed in Newark. This is war. Ray Cifarelli identifies two Curtis-connected distributors operating inside Bellotti territory and has them removed quietly. Mick takes sole control of the Elizabeth shipping route and runs it fourteen hours a day. Rudy meets a woman named Deb at a bar in Burlington and goes home with her. He lies awake at three in the morning thinking about Elena, whom he still loves.

It’s a war between Curtis and the Bellotis, with each of them making move after move. Ray pulls Vincent aside and tells him that Tony built a sealed fuel depot under the Elizabeth docks in 1987 that Curtis is unaware of, and that the access tunnels run directly under Curtis's main holding yard. Mick drives out to the outskirts, to the property Vincent bought in season two, and sits alone in the unfinished house, then calls Vincent and tells him he is done after this. Elena finds out she is banned from working on any Belloti cases. Rudy and Deb spend a morning together, and he watches her leave without saying what he is thinking. That night, Vincent gets a phone call from Curtis. He speeds to the bar, but is already burning when he pulls up. He stands in the street, watching the bar burn, the place he grew up in, rotating in and out of it for all his life. It burns. He calls Rudy.

Rudy drives to Newark. The Bellotis plan. Dominic and Rudy take the tunnel route under the yard while Vincent and Mick hold the street. Ray runs a separate play, pulling a Curtis-aligned distributor out of a parking garage alone and extracting the location of Curtis's exit route. The yard assault goes into play and Curtis's men scatter toward the beach. Ray cuts off the exit road. The standoff forms on the waterfront at night with both sides armed and nowhere to go. Curtis shoots Mick in the head at close range without warning. Vincent pulls the tunnel charges Ray wired under the yard and the holding operation collapses behind Curtis, destroying his supply chain and cutting off his remaining crew. Curtis is cut off from his final words and is shot and killed. The siblings mourn over Mick, having a big argument about everything and whose fault it is, while Mick just lies there, lifeless. By morning, the Bellottis are gone and the beach is clean. Rudy does not go back to Vermont.

The Bellotis sell the land where the bar used to be, marking the end of an era. Rudy spends the day moving through Newark alone. He goes to Elena's apartment, and they spend time together, talking, before he leaves without saying what he came to say. He tracks down an old lieutenant named Sal who was present the night Juan died. Sal tells him that Juan discovered Rudy had been quietly protecting the Bellottis and forced Rudy to execute him at gunpoint as a loyalty test, with his men watching and a threat against everyone Rudy cared about if he refused. The beating they gave him after took his memory of the killing. Rudy forgives Sal and walks out. He spends the rest of the day visiting people across Newark, then drives back to Vermont and calls Deb from a rest stop.

The family buries Mick privately while Newark police list him as missing. Missing posters go up across the city. Elena discovers her Bellotti case folder has been stolen from her desk, documentation that no one outside her office knew existed. It contains information that would be very dangerous if it fell into the wrong hands. Ray Cifarelli routes a shipment through a federally surveilled port channel and spends the day racing to intercept it before agents open the container, burning a contact who gets arrested in the process. The Bellottis now run the largest drug and cargo operation in the tri-state area, and Vincent is the boss. Suddenly, Carla goes missing. Sean calls Vincent and tells him to bring Dominic to Suite Osmanthus unarmed in two hours. Vincent and Dominic drive. Sean walks them through the door. Carla is already sitting at the table.

Sean sits Vincent, Dominic, and Carla around the table and works through Elena's stolen folder, which documents Tony's private conduct over the years. Tony’s abuse. He builds toward one point: Dominic ordered Tony killed because of the sustained abuse Tony inflicted on his children and the damage his decisions caused everyone around him. Vincent pushes back on every piece. Sean lays out the documentation until Vincent has nothing left to counter. Vincent charges at Dominic, and Sean physically separates them. Sean walks Dominic out and releases him, then leaves without explanation. Dominic has a panic attack in an alleyway. Vincent and Carla sit alone in the empty suite. Vincent decides aloud that none of it happened, and he will not accept it. Carla watches him and says nothing, knowing denial and Stockholm syndrome when she sees it. Sean drives away from the building, a quiet smile on his face, knowing he has fractured this family and, hopefully, their operation forever.

Dominic is still having a panic attack, and we see flashbacks showing Dominic arranging Tony's murder: who he called, and why. A stranger in the alley sits with him through the panic attack. Vincent and Carla go back to Newark. Vincent, in denial of his father's abuse and furious at Dominic, takes full unilateral control of the operation, making violent and risky decisions, overriding every decision Ray and Carla put to him. Ray and Carla, wary of Vincent's increasingly unstable decisions, agree to move against Vincent and pull control of the operation away before he destroys it. They plan.

Carla and Ray gather as many people who would agree as they can to move against Vincent. They confront Vincent, guns out, but Vincent anticipates the move and has his own bigger crew. They nearly kill Ray before he gets out, bloodied. Vincent keeps Carla safe and alive, telling her to never rebel against him again. Meanwhile, Ray drives to Elena and the FBI and hands over a full accounting of the Bellotti operation, every name and every transaction, deliberately leaving Carla out of all of it. Elena files it with the FBI, and warrants go out to take down the Belloti organization. Dominic drives to Mick's grave and sits beside it, talking to him. In Vermont, Rudy proposes to Deb, and she says yes, joyfully.

Rudy and Deb sing “Forever Young” in karaoke, then drive home fast with the windows open, taking in the moment. At the house, Rudy walks into the living room. Deb is watching the news. His face is on it, listed as a wanted person. He begs her not to call the police. She calls them anyway. He watches her do it, hopelessly, then walks out the front door, gets in his car, and drives away. Deb watches him go from the window, with tears in her eyes. The FBI raids every Bellotti warehouse and operation in Newark simultaneously, and the operation collapses. Vincent escapes and drives toward Dominic, believing this to be all his fault. Carla finds Dominic first. Vincent locates them both in a random parking lot at night in the rain, forces Carla aside, and puts a gun to Dominic's head. Dominic goes to his knees. Vincent and Dominic have one final talk, as Carla begs Vincent not to fire. Vincent shoots Dominic in the head and leaves. Dominic is left dead in the rain as Vincent drives away.

Carla, heartbroken, just leaves Dominic in the parking lot. Vincent discovers Ray was the source behind the FBI warrants. He threatens Ray until he walks into the federal building and claims he fabricated the entire case out of personal grievance. Ray is arrested for filing a false complaint and the warrants dissolve. Elena knows it is a lie but cannot prove it and keeps the investigation open. Sean returns to Newark and meets with Vincent alone. They have a final, bitter talk. After Sean leaves, a call comes in confirming Sean has taken Elena because of the case she continued to build. Vincent tells Carla. Carla calls Rudy with the location and they drive toward the docks. Carla and Rudy reach the Elizabeth docks where Sean is carrying Elena's body toward the water. She is already dead. Rudy has a gun but does not fire. Sean backs to his car and leaves. Rudy stays. He tells Carla to go, calls the police, and waits on the dock alone for them to arrest him. He will take the blame.

Carla visits their old house that was never sold and takes a VHS from it. Carla goes to Vincent's apartment, hands him the VHS tape, says goodbye as they have one final chat, and leaves. He puts the VHS aside. Six months later: Vincent runs the largest operation in Newark and lives in a penthouse. He hosts a dinner for the 2-year anniversary of Tony's death. Rudy and Ray share a jail cell. Sean is in Spain under a new name. Carla lives in the outskirts house and sells paintings. Vincent finally watches the VHS. It is his childhood with Carla, Dominic, Rosalie, and Tony. He sobs through it and memories of Tony's abuse come back fully. He realizes he has done terrible things, and for what. The last shot is Vincent on the balcony looking over Newark, a unique sadness in his eyes. He is on top, but completely alone and with the knowledge that everything he has done was wrong. “The World is Yours” by Nas plays as the screen fades to black. The world is his, but at what cost?