A massive meteor has struck Tokyo. Arisu, Usagi, Chishiya, Aguni, Niragi, Kuina, and all the other survivors were caught in the blast. They were clinically dead for one minute. The "Borderland" was a shared near-death experience—a purgatory where their will to live was tested through the games. Each card they cleared was a step back toward life.
As the Queen of Hearts falls, all remaining games end simultaneously. But the King of Spades, whose "game" was to hunt endlessly, goes berserk. He arrives at the Queen’s garden, mowing down the exhausted survivors. In a desperate, bloody, and spectacularly choreographed final battle, the remaining major characters—Aguni, Niragi, Chishiya, Usagi, and a newly-resolute Arisu—throw everything they have at him. One by one, they are shot down. Aguni sacrifices himself to pin the King’s arm. Chishiya takes a bullet to shield Usagi. Finally, Arisu, using a discarded grenade, blows up the King’s weapon and impales him with a metal pipe.
The illusion shatters. Mira, genuinely moved, forfeits. Her face card melts away.
Arisu, Usagi, and their new ally, the stoic martial artist Aguni (Shō Aoyagi), are captured by the King of Spades and forced to flee into a massive, abandoned prison. They are immediately sucked into the game. This is a psychological horror show. The rules: seven players are locked in a cell block. One is secretly the "Jack." Every few minutes, there is a "vote" where everyone guesses who the Jack is. If the majority votes correctly, the Jack dies. If they vote incorrectly, everyone else dies. The catch? The Jack knows who they are, and the only way to win is to deduce the Jack's identity while avoiding paranoia and betrayal.
Meanwhile, a separate group—including the cheerful climber Kyuma and the pragmatic Tatta—enters a massive, multi-level botanical garden. This is the game: "Osmosis." Two teams (the "Invaders" and the "Defenders") compete to control a central "base." The twist is that every time a player tags an opponent, they switch teams. Loyalty is fluid; your enemy today is your ally in five minutes. The King (a charismatic, shirtless man with a philosopher’s streak) leads the Defenders. He doesn't fight to win; he fights to evolve the players. The game is less a battle and more a dance of shifting alliances. Through self-sacrifice and brilliant improvisation, the group (led by the tactical genius of a reformed gangster named Niragi) finally corners the King. As the King accepts his defeat, he congratulates them on "becoming a team," a stark contrast to the Beach's selfishness.
Chishiya, separated from Arisu, wanders into a minimalist, glass-walled room. The is a game of pure, cold intellect: "Beauty Contest." Players are given a number (0-100) and must guess a number that is 0.8 times the average of all players' guesses. The closest wins. The King, a prodigy named Kuzuryū, is a former lawyer who believes that truth is a logical construct. The game is a recursive nightmare of nested calculations. Chishiya, a former doctor who despises emotional investment, tries to play it purely statistically. But he realizes that perfect logic leads to a dead end (the Nash equilibrium is everyone choosing 0). The only way to win is to predict human irrationality. In the final round, Chishiya abandons pure math and takes a leap of faith, guessing a number that accounts for the King's own hubris. He wins. The King, defeated, reveals his own secret: he wanted to lose, to be proven that human intuition can defeat cold logic.
Their grim recovery is shattered by the arrival of a drone, carrying a single, terrifying message: The game has entered its final phase. All number cards (Two through Ten) have been cleared. What remain are the twelve Face Cards: The Jack, Queen, and King of Spades, Clubs, Diamonds, and Hearts. These are no mere dealers; they are former players who chose to become permanent residents of the Borderland—the "Citizens." Each game is now a boss battle, designed by a master of their suit.