After the doomsday nuclear war, a mysterious game descends, and players from various countries are forced to participate in a nationwide game of hide-and-seek, where losers see their territories fall. The Dragon Country is randomly chosen to have Lin Sui'an, a young girl who has been locked in a psychiatric hospital for fifteen years. She is naturally able to see what ordinary people cannot, yet she is viewed as crazy by the world. While others hide desperately, she calmly eats cake, deconstructs rules, and counter-kills the supernatural, winning three consecutive S-class rewards, saving teammates, reclaiming lost territory, and becoming the patron saint pursued by the entire nation. However, as the dungeon upgrades, the mystery of her identity and the truth of the game gradually come to light.