Patients begin to die one by one under mysterious circumstances in a mental hospital. A young nurse named Ikuko Matsuda doubts that these deaths were natural. On day, Ikuko disappears, leaving behind a blood-stained cash card. Her fiance Katsuyoshi Yamazaki ventures into the hospital, attempting to investigate the mystery.

Patients begin to die one by one under mysterious circumstances in a mental hospital. A young nurse named Ikuko Matsuda doubts that these deaths were natural. On day, Ikuko disappears, leaving behind a blood-stained cash card. Her fiance Katsuyoshi Yamazaki ventures into the hospital, attempting to investigate the mystery.