In a post-apocalyptic ice age future, a seal hunter named Essex, travels north with his companion Vivia, who is the daughter of Essex’s deceased hunting partner. The couple walks across a barren, snow-covered landscape towards a city where Essex once lived. Along the way, they pass a pack of Rottweiler dogs feeding on a human corpse, which has become a common occurrence, but they also spot a goose flying, which Essex has not seen in years. As they rest inside an abandoned structure, Vivia, child-like and naïve about the world, asks Essex once again to describe his memories of the city. Essex says the metropolis of five million inhabitants had twenty-five levels and five sectors, plus a park with a lake and trees. After Essex and Vivia arrive in the sparsely populated and ruined city, Essex attempts to locate his brother, Francha, but is unsure if he is still alive. At the non-functioning information center, Essex is able to decipher Francha’s address from the extant data. When the brothers reunite, Francha is thrilled that Essex, whom he assumed was dead, has returned. Essex explains that he has been hunting seals in the south for the last decade, but the population is now depleted. Amazed by Vivia’s youth, Francha speculates that she might be the last person born. As Vivia removes her outer garments, Francha and his female companions, Jaspera and Aeon, are astonished to see that the young woman is pregnant, a rarity in the current world. Francha suggests they celebrate by playing the six-person board game, Quintet, which has become the primary activity and obsession for many inhabitants, since work now seems meaningless in their dying civilization. Each player requires three matching game pieces, which often reflect his or her personality, and some players wear their game pieces as identification tags. Francha offers to give Essex a set, but Essex is not interested in playing and leaves to buy firewood at the market, and inquire about employment. While he is away, a Quintet gambler named Redstone detonates an explosive at Francha’s apartment. Essex rushes back when he sees the blast and finds everyone inside dead, including Vivia. Kneeling beside her body, he grabs a stick for a weapon and pursues Redstone, whom he saw near the apartment. However, another Quintet gambler, St. Christopher, slits Redstone’s throat, then quickly departs the scene. In Redstone’s bag, Essex finds personalized Quintet game pieces and a list of six names: Francha, Redstone, Goldstar, Deuca, St. Christopher, and Ambrosia. Essex buries Vivia in the river before hungry dogs have a chance to mangle her corpse, then investigates the explosion that killed her. After locating Redstone’s address, Essex learns that the gambler has reserved a room at the Hotel Electra for a Quintet tournament. Arriving at the hotel, Essex poses as Redstone and wears the man’s game piece around his neck. The female innkeeper, Deuca, assigns Essex a room, while Grigor, the Quintet casino referee, observes him with interest, knowing that Essex is an impostor. Later, Grigor tries to befriend Essex and explains that, as referee, he establishes rules and settles disputes, but is not allowed to play. He invites Essex to join a game of Quintet at the hotel that evening. Among the participants is an expert female player named Ambrosia. In the first round, she rolls the highest number with the dice, earning the advantage of being the “Sixth Man” and proceeding directly to final round, known as the end game. She awaits the winner from the five remaining players, who try to purge each other by means of dice rolls and board moves. Elimination of a player is known as a “killing.” Meanwhile, Grigor returns to the casino. Along the way, he is approached by St. Christopher, who is anxious to know how they should proceed with the tournament now that a man posing as Redstone has arrived, but Grigor wants to learn more about the mysterious intruder before issuing a ruling. St. Christopher is also angry that the real Redstone unnecessarily massacred everyone in the apartment, just to murder Francha, and believes the action betrays the ethics of the tournament. Back at the hotel, Ambrosia emerges the winner of the board game after eliminating Essex in the final round. During the night, Essex continues his investigation of the names on the list and overhears the gambler Goldstar telling Ambrosia that he will enjoy murdering St. Christopher, whom Essex later learns is the most skillful Quintet player and runs a charity house. Meanwhile, Goldstar loses his opportunity to confront St. Christopher and is fatally stabbed by Deuca. Elsewhere, Essex becomes friendly with Ambrosia, who resides in the adjacent hotel room. When they discover Goldstar’s corpse, Essex interrogates Ambrosia about the ritual killings and also discloses his true identity. Although evasive about the meaning of the list, Ambrosia is touched by Essex’s old-fashioned, hopeful view of the world and reminds him that avoiding death is pointless since civilization will soon end as the world freezes. Lonely, Ambrosia asks Essex to spend the night with her. The next day, hoping to glean information about the impostor’s identity and purpose, Grigor invites Essex for a drink of booza, the local liquor; Essex, pretending to be intoxicated, frustrates Grigor by rambling incoherently. St. Christopher arrives at the bar and agrees to escort the impostor back to his room, where he has the chance to murder Essex. However, St. Christopher refrains, since the impostor is not officially on the kill list. Later that night, the fourth player in the tournament, Deuca, is stabbed to death by St. Christopher. As the winner of the front game, St. Christopher declares to Grigor that he is ready to face Ambrosia, who has been waiting on the sidelines of the tournament as the “Sixth Man.” However, Ambrosia insists that the man who claims to be “Redstone,” even if he is an impostor, must be killed first. Agreeing with her, Grigor rules that the impostor has unknowingly become a player in the tournament and must be eliminated if St. Christopher wants to advance to the final round. St. Christopher defers to Grigor’s decision and leaves to assassinate Essex. As Essex walks to his brother’s sector, St. Christopher confronts him, but during the chase, St. Christopher falls through a cavity in the snow and is impaled on his own spear. Arriving at Francha’s apartment, Essex locates his brother’s list, which contains the same six names as Redstone’s list, confirming that the tournament is a Quintet game of real killings. Unexpectedly, Ambrosia arrives and approaches Essex with a concealed knife, but Essex slits her throat, realizing that he is now a player and must kill or be killed. At the casino, he deposits Ambrosia’s body in a fire pit in front of Grigor and declares himself the winner, but also reveals his contempt for the deadly game. As Grigor tries to convince the impostor to stay in the city and be a great Quintet player, Essex leaves and walks north, hoping to find another way to survive.