Now based in the United States, Johan “JW” Westlund Joel Kinnaman keeps pressing to uncover the fate of his missing sister Camilla Westlund Maja Kin. Through careful sleuthing, he learns that Camilla fell under the influence of a Serbian mob boss, Radovan Saša Petrović, eventually becoming involved as an exotic dancer and a mistress. When Radovan discovers Camilla plans to walk away, his volatile second-in-command, Stefanovic Čedomir Đorđević, orders her murder to send a brutal message to the others.
Back in Sweden, Radovan survives an assassination attempt and, to shield his only surviving child, Natalie Krajnic Malin Buska, he assigns his trusted subordinate Martin Hägerström Martin Wallström to watch over her. Unbeknownst to Radovan, Martin is an undercover officer intent on bringing him to justice. Martin has managed to infiltrate the mob with information supplied by the incarcerated Jorge Matias Varela, who is released early for his cooperation and reassigned to work at a nursing home. There, Jorge forms a bond with Nadja Madeleine Martin, a former sex slave, and the two begin a relationship. While Nadja aims to steer clear of crime, Jorge secretly plans a major robbery for Finnen Mats Andersson, a Swedish mob boss, believing this will allow him to retire.
The heist succeeds but ends in a brutal double-cross by Finnen. Jorge is the only survivor, escaping with a bag of money and fleeing to Mexico. He then contacts Nadja, who reveals that she is pregnant. Meanwhile, Martin and Natalie grow closer, sharing a fragile romance. Radovan realizes Martin’s true identity, but is killed when a car bomb explodes before he can act on it. Natalie, convinced that Stefanovic engineered the hit, makes a failed attempt to take him out; Martin intervenes to protect her and ends up killing Stefanovic, leaving Natalie in a position of power within the mob.
When Jorge contacts Nadja again, he learns she has been kidnapped by Finnen and will only be released in exchange for the remaining money. He reaches out to Martin for help, and the two confront Finnen and his men. Martin succeeds in rescuing Nadja, even as Jorge engages Finnen in a fierce gunfight and appears to die in an explosion. Natalie's trust in Martin is shaken when she discovers his undercover status, and she confronts him upon his return, but she ultimately grants him a narrow escape. The revelation that JW orchestrated his sister’s murder in retaliation for Camilla’s death drives Natalie to track him down and exact revenge, and she personally executes JW.
Two weeks after Jorge’s supposed death, Nadja learns that he is very much alive. She discovers that he faked his death, killing Finnen and his men to seize the remaining money, and he writes a letter inviting Nadja to join him in a new life in Mexico. She accepts, and the couple reunites, stepping into a future that is both dangerous and hopeful, with Nadja carrying their child forward.
