A classic-style mystery in which university mystery-club members Hamura Yuzuru and Akechi Kyosuke, together with detective Kenzaki Hiruko, visit the film club's retreat at Shijinsou and are drawn into an unforeseen crisis and a locked-in setting. It fuses extreme suspense with logical detection.

In the midst of despair, a bizarre premise and a fair-play puzzle are locked together.