Arisu gasps awake. He is not in a magical arena. He is in the rubble of the Shibuya Crossing in Tokyo. But there is no fire, no lasers. There is rain. And sirens. He is lying in a puddle of water, his heart barely beating.

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.

Every single one chooses to refuse. They walk through the light.

Arisu and Usagi, battered and separated from the others, finally reach the final arena: a psychedelic, dream-like garden filled with giant playing cards and candy-colored trees. Here awaits the : Mira Kano, a serene, smiling psychiatrist. Her game is deceptively simple: a single round of croquet. The twist? Every time a player misses a shot, they are injected with a hallucinogenic drug that brings their deepest traumas to life.

In the real world, paramedics find them in the debris. Arisu and Usagi are loaded into separate ambulances. As the doors close, Arisu sees a vision of Mira, the Queen of Hearts, standing in the rain, smiling. She mouths the words: "Until next time."

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.