Jiang Xiu, in the final stage of brain cancer, is pulled into an otherworldly live-stream horror game. The system promises that winning the championship will cure her illness. In the trial map, she draws a Joker card — an undercover identity facing one versus all — but she refuses to play by the rules and blows up the train to clear the level directly. Afterward, she breaks through multiple maps in a row, gaining resources and viewers through gameplay like roulette and mystery boxes. Within five days, she rises from a newcomer to Rank A and defeats the Three-Headed Bug of the Class C club. Along the way, she recruits indebted player Zhang Jianyi, forms an alliance with Xuanyuan Ting of the Blood Sea Alliance, and strikes a "mutual trade" agreement with the system, gaining the authority to rescue players who die within the game.