Three months after his sister disappeared, Chen Xu suddenly received her WeChat message: At 11:30 tonight, come to Nanhuai University 404. The old building late at night, the fourth floor that appeared out of thin air, the wet-haired woman calling his name in the bathroom, "myself" who looked exactly like him... Everyone was lying to him, but they all seemed to have truly loved him. His sister told him not to believe Lin Wan, but Lin Wan whispered into his ear in the dark to save him. But why are the people who died in 404 three years ago still waiting for him? And on that rainy night that he forgot, who left whom at the door first? After one o'clock, 404 allowed only one person to get out alive.
