At midnight, the copper lock knocks three times, and Shen Zhaoning’s door opens again. The symbols left behind by her younger sister, who died under mysterious circumstances three years ago, reappear in her dreams. Gu Huaisheng, a reporter who vanished and has now returned, says it isn’t a dream. The Soul-Locking Gate is choosing someone. When the sleeping pills handed to her by a psychiatrist conceal a sealing spell, and a runaway girl counts the knocks and says, “The seventh one. It’s your turn,” Shen Zhaoning finally understands: she isn’t the one searching for the truth. The dead are waiting for her to open the door with her own hands.