"Recording Demon" is wreaking havoc. Wearing a headset, she points a professional-level microphone at each shower room, then threatens everyone with her recorded singing voice. During an operation, Detective Q successfully arrests the "Recording Demon," but when he returns home, he receives a threatening letter from the "Recording Demon" along with a recording of his own terrifying singing voice. To prevent his voice from being made public, Q follows the instructions of the "Recording Demon" while pursuing the truth of the incident.