[6] Young-eon (Kim Ok-vin), the top singer at an all-girls school, is murdered by a music sheet cutting her throat in the opening scene.

Seon-min befriends a strange and lonely girl at school named Cho-ah (Cha Ye-ryun), who can hear the voices of the dead, and she decides to help the two.

It turns out that Young-eon had previously had a rivalry with Hyo-jung due to their similar voices and began to wish that the teacher was dead in order to cause Hyo-jung, who was in love with the teacher, to quit music, and that in an intense confrontation the two had actually killed each other.

Young-eon flies into a rage and kills Cho-ah and takes over Seon-min's body.

A scene during the credits shows Cho-ah shouting in frustration, but as she is voiceless, no sound comes out.