The high schoolers met a mysterious figure who claimed to be the overseer of the underworld. To their astonishment, the figure joined their class' WeChat group and started assigning them tasks. Money rewards awaited those who accomplished the tasks, which thrilled the students at first. However, their excitement quickly vanished once they learned that not fulfilling their given duty meant death. Consequently, the "underworld gatekeeper" reduced the entire class to helpless puppets.