After two years in the US, Na Na returns to Beijing and looks up old friend Song Qi An, now taking a postgraduate course in psychology. Na Na asks her about others from their group at university: ambitious You Feng now works in a technology company and is due to marry the daughter of the chairman, Yu Fei is now an up-and-coming actress, and Yang Zheng is now a journalist after wanting to become a film director. Na Na especially wants to know about Hong Rui, whom she always fancied, and learns his father went bankrupt and he himself is now lame from an accident and works on a building site.

Na Na, who was rumoured to have had mental treatment in the US, tells Song Qi An that another member of the group, Xiao Ai, who committed suicide at college, is haunting her. (Her belief in ghosts goes back to her childhood in the countryside, when a school friend, Yu Han, gave her a weird doll.) When Nana visits her old friends, they all react angrily to her mentioning Xiao Ai. Na Na remembers how, back in 2010, it was she who befriended Xiao Ai, a Chinese literature student, and brought her into the group. To her annoyance, Hong Rui had fallen for Xiao Ai, and when misfortunes started to happen, Na Na had blamed Xiao Ai as an evil influence. To settle the problem, the friends had played the ouija board-like game of Bixian, which revealed the name of Yu Han. After Na Na had exposed Xiao Ai as the grown-up Yu Han, Song Qi An had walked out, appalled; that evening, Xiao Ai had thrown herself off a college building. Back in the present day, members of the group now start getting killed by a ghostly presence.