Arisu Ryohei and Chota were searching for clues, trying to figure out how to return to their world. Oori used a pot she had scavenged to cook a warm meal for everyone. At the dinner table, everyone discussed how they had arrived in this realm. Arisu and the others learned that Oori had entered the game three days ago and was the only survivor. Arisu believed that since this was a game, there must be a game master overseeing it.
That night, Karube privately spoke with Arisu, suggesting that only the two of them participate in the next game. This way, they could secure ample survival time if they won, and also take care of the injured Chota. They then hurried to the game venue, where they encountered Usagi Yuzuya, Kūya Shuntarō, Nitoibu, and Aguni, among others. This game had 13 participants and was rated Five of Spades in difficulty. Based on information provided by Nitoibu, Arisu and Karube learned that the suit of the playing card typically indicated the type of game: Spades relied on physical strength, Clubs on teamwork, Diamonds on intelligence, and Hearts on manipulating people and betraying allies. The number represented the difficulty level, with higher numbers indicating greater difficulty.
Meanwhile, Chota was speaking with Oori. Oori asked Chota if he was willing to die for his friends. Chota suddenly recalled past events and tears welled up in his eyes. Oori kissed Chota and told him the truth, believing that Chota was like her. Chota began reminiscing again and prayed to the Virgin Mary to save everyone.
The game was called "Hide and Seek." The rules were simple: within 20 minutes, players must avoid being caught by the "demon," find the base in a certain room of the apartment building, and touch an object in the base to succeed. If the time limit was exceeded, the building would explode.
The game officially began, and the players spread across different floors to search for the base. Kūya Shuntarō ran to the top floor to observe the movements of the players below. Arisu Ryohei, Karube, and Nitoibu formed a team and searched the fifth floor. While climbing the stairs, they heard gunshots and soon saw the body of a player rolling down from upstairs. Immediately after, they encountered a person wearing a horse-head mask—the "demon"—who raised a gun and fired at them. The three hurried downstairs and became separated from Nitoibu during the chase.
The demon shot and killed several players one after another. With eight minutes left, Arisu successfully rescued a player from the demon’s grasp. At the staircase, they encountered Aguni and another player. Aguni invited Karube to join him in hunting the demon, while instructing Arisu to continue searching for the base. Usagi Yuzuya appeared and informed Arisu that the south area of the fifth floor and the south and east areas of the sixth floor had already been searched. She then rushed to search the first and second floors.
With five minutes left, Aguni ordered another player to lure the demon over. However, when the player led the demon to them, Aguni made no effort to save him, and the player was killed. At this moment, Karube was only a few steps away from the demon. Aguni charged forward to fight the demon, and Karube joined the battle, sustaining injuries in the process.
With three minutes left, Arisu and Kūya Shuntarō simultaneously discovered the base. They opened the door, only to be met by another demon who opened fire. Arisu hurriedly hid inside the room, while Kūya ducked outside the door. Arisu realized that two people were needed to press buttons on both sides simultaneously to clear the level. Arisu opened the window and shouted for help. Usagi Yuzuya heard his cries and rushed to join him.
The demon broke through the door, and Arisu wrestled with it. Kūya Shuntarō tossed a stun baton he had found to Arisu. At that critical moment, Usagi leaped into the room through the window, and Arisu used the stun baton to incapacitate the demon. With seconds to spare, Arisu and Usagi pressed the buttons simultaneously, successfully clearing the game. The two demons died instantly.
Karube found a walkie-talkie on the body of a player. The device repeatedly transmitted a message: "We have found the answer. Return to the Beach..."