Delusion is a 2016 Chinese-Hong Kong suspense thriller film directed by Danny Pang Phat and starring Pakho Chau, An Hu, Cici and Cheng Yuanyuan.

One day she meets Yu Wenle on the street, who looks like the‘him’ in her diary, so she doesn't care who he is or whether he has a girlfriend or not, she brings him home, cooks for him, and falls in love with him.

Except for Leung Loh Sze, who occasionally talks to her, she spends most of the time alone, cooking, making puppets, writing in her diary, and staying in a daze.

Li Wei, investigating a series of bizarre murders, discovers clues related to delusional patients.

As the plot progresses, the three storylines converge, revealing a shocking truth: behind Lin Zichen's novel and Li Wei's cases lies a massive psychological experiment.