The walls are closing in on Marcus and his remaining crew as law enforcement turns Newark into a high-pressure zone. With their power structure failing and the city hunting them, they are forced into hiding. Paul Rinaldi continues his relentless pursuit, leading to a final confrontation where all parties must face the consequences of their long involvement in the drug trade in the final season of The Line.
Picking up seconds after the gunshot, a panting Reggie carries a bleeding, semi-conscious Marcus through the woods in a desperate search for his car. Arriving at the forest too late, Paul finds Corey’s lifeless body, realizing with sadness that Marcus has somehow slipped away again. As a tense cat-and-mouse chase ensues through the dark forest, Reggie temporarily hides a deteriorating Marcus by a water fountain. A delusional Marcus unravels into a state of self-hatred, stating that he deserves death as punishment for killing people, and for death so he can finally reunite with his brother Desmond. Reggie leaves Marcus there once he falls asleep to search for food to eat, since they are starving in the forest. The search erupts into a shootout with Paul who finds Reggie, and Reggie is forced to grab Marcus and make one final, frantic sprint to the vehicle, barely escaping as they drive off and Paul’s gunfire misses their tires.
Hours after the bloodshed in the woods, a panicked Reggie smuggles a delirious, heavily bleeding Marcus into a abandoned basement apartment on the outskirts of Newark. Reggie is forced to blackmail a terrified street doctor to perform an agonizing surgery on Marcus's wounds without anesthesia. As Marcus drifts between consciousness and sweating, horrific nightmares of Desmond, Corey, Daniel and Mac, Paul uses the fallout of Corey’s murder to bypass local red tape, convincing a federal task force to plaster Marcus and Reggie’s faces across the national news. Meanwhile, a traumatized Nicole is subjected to a FBI interrogation, having to lie about what her husband has done and what she has done, since she was once in the drug business too.
Marcus finally breaks his fever, but the physical recovery brings an unhinged psychological collapse. Refusing to eat and trapped in the suffocating basement, a broken Marcus aggressively lashes out at Reggie, screaming that he should have let Corey pull the trigger in the woods. Marcus attacks Reggie, who refuses to fight back, as Marcus begs him to just end his life. Outside, Paul's federal manhunt turns Newark into a police zone, raiding Marcus’s old blocks and choking out the remains of their empire. Meanwhile, Daniel's little brother, Mikey, struggles with a paralyzing sense of guilt after seeing Marcus's face on television, leaving him deeply tempted to approach Paul and confess everything he knows just to get justice for his dead brother.
Running dangerously low on cash and medical supplies, an increasingly desperate Reggie is forced to arrange a covert meeting with one of their last remaining mid-level suppliers to demand a final payout. Sensing weakness, the supplier ambushes Reggie, forcing the crew's former moral anchor to fight back. Reggie brutally injures the dealer to escape with the cash, sparing his life. Meanwhile, Paul grows furious with the Federal Task Force, realizing their loud, bureaucratic way of handling the investigation is actively disrupting his own vigilante methods. When a tech team intercepts a brief cell phone ping from one of Marcus's old drug associates, Paul secretly breaks away from the feds, intent on tracking the lead down himself before the government can ruin his chance.
As Marcus's fever breaks, his old survival instincts kick back in. Refusing to stay hidden in the basement, he risks leaving the basement to scout the changing turf of Newark, trying to get back what is left of his broken drug empire. Left entirely alone in the suffocating hideout and driven mad by the thoughts of his child, a lonely Reggie slips out to a street payphone to call Nicole, begging her to take the child and flee. However, Paul has already gone rogue from the FBI task force; using his own methods, Paul tortures a local informant to be able to get the FBI’s live wiretap interface onto a private laptop. After Reggie calls a tearful Nicole, both Paul and the FBI arrive at the coordinates, forcing a terrified Reggie into an escape.
With their basement hideout permanently compromised after Paul and the FBI's ambush at the payphone, a shaken Reggie and a fully recovered Marcus are forced onto the move, taking temporary shelter in a decaying graveyard located at the edge of Newark. Knowing the federal task force are tightening around every exit out of New Jersey, Marcus begins to make a plan for a desperate heist to dig up their last remaining buried asset, a massive stash of drug money hidden beneath a local Newark storefront they used to front. As Marcus focuses on the plan of the robbery, Reggie is quietly destroyed by the realization that Marcus’s ultimate plan involves purchasing international passports to cross the border and leave Newark, forcing Reggie to accept that to survive, he must permanently abandon Nicole and his child.
The final descent begins as Marcus and Reggie execute their midnight raid on their own former property, successfully getting the hidden stash of cash while federal patrol cars cross the streets just blocks away. However, the victory is short lived; back at their temporary base, the graveyard, Reggie refuses to leave the country. Marcus coldly reminds Reggie that his life as a peaceful family man died the second he put a bullet through Corey's head. Meanwhile, a relentless Paul discovers the excavated stash spot, realizing Marcus is actively grabbing assets to flee, prompting Paul to use his own wiretaps to track Nicole's location. Paul realises that Nicole is the final bait he needs to lure Marcus and Reggie out.
Paul captures Nicole after she escapes federal custody, forcing her at gunpoint to call Reggie to arrange a meeting at his location,the graveyard. When Nicole arrives wearing a wire, a paranoid Marcus spots the trap. Realizing she is working with Paul, Marcus ruthlessly shoots Nicole on the spot. A devastated Reggie completely snaps, throwing himself at Marcus in a savage brawl across the cemetery. Paul races down from his distant vantage point to intervene the fight, but it's pitch black, and he can't see. The fight between Marcus and Reggie ends near a ruined monument, where Marcus accidentally impales Reggie on the broken stone wing of an angel statue. As a sobbing, terrified Marcus tries to pull him off, saying that he didn't mean to impale him, a dying Reggie weakly tells him to stop. He tells him that he's ruined too many lives for too long, and that he needs to stop. Reggie quietly dies. Marcus flees into the night just as Paul finally reaches the graveyard.
Marcus speeds blindly through Newark, sobbing in the driver’s seat as the horror of Reggie’s death collapses on him and his face flashes across national news. Behind him, Paul is in his car. Meanwhile, Mikey, the crew's only survivor, watches in silence as the news announces the deaths of Reggie and Nicole. Bleeding from his wounds, Marcus ditches his car at an abandoned factory, but Paul arrives instantly and opens fire, striking Marcus in the leg and stomach. Marcus fires back, hitting Paul’s shoulder to buy time to drag himself inside. A tense cat-and-mouse chase ensues inside the factory until Paul disarms a bleeding Marcus. As Marcus crawls on the floor and begs for death, Paul realizes killing him would be a favor. Shaking his head, Paul says, "You've already killed yourself," and walks away. Decades later, a broken, 41-year-old Marcus lives anonymously on Avon Street, sitting alone on a bench in his empty childhood court. He lost everything, and for what?