Synopsis：One year after graduation, Yang Xinyi organizes a group of former classmates to revisit their old campus. Upon arrival, Han Gaofei encounters a mysterious masked figure in the restroom and is attacked, his fate unknown. The group returns to their villa, where the masked figure reappears in the dead of night, strangles Yang Huihui, and then pursues Lin Bing, who has become a witness. Suspicion falls on Xu Zhiyi, who has mysteriously disappeared, but they accidentally discover that Xu Zhiyi had already been strangled to death. As the mystery deepens, Han Gaofei and Luo Ou argue and suspect each other, both bringing up the disappearance case of Jia Zhongming from a year ago. It is then that the group is shocked to realize that today’s tragedy is closely linked to the disappearance case from the previous year. Is it man-made or supernatural? Intentional or coincidental? Amidst all the puzzles, a conspiracy gradually emerges.