An invitation to the final audition held at a four-day training camp has been sent to seven actors belonging to the theater company. The scenario they "act" in the final selection for the lead role in the new stage play is a serial murder case that occurs in a fictitious situation called [Mountain Villa Closed by Heavy Snow]. The members disappeared one by one in a closed room with no exit. Is this fiction? Or is it a true serial killer? What is the shocking ending that awaits them?