The protagonist, Erin Hunter, was originally a very ordinary college student who "traveled" to the fifth personality by chance. In a coma, she realized the murderer Irene Pumansha. The latter claimed to have entered her body. During the journey to find the Frozen Heart, she became aware of her own life experience, and when she returned to the manor, she wanted to make the truth surface through investigation. On the night she comes back, all the truth will be revealed...