Iron Snake Mask's plot involved tormenting the small town of Hebigami, where she emerged at night and sucked the blood of young women in the town until they died. After four reported murders, Peggy receives a letter from another female from the town who asks to be protected from the murderous "snake woman" that has invaded. Peggy decdies to take up the invitation and assist in taking down the snake-woman, but Iron Snake Mask instead tries to attack her during the stay and sucks out some of her blood, making her become weaker in the process.