A mysterious person who claims to be the gatekeeper of the underworld suddenly joined the class WeChat group of high school students. This person started posting tasks to the group and rewarded those who completed them with money. At the start, the students were thrilled to receive rewards for completing the tasks. However, it did not take long for them to learn that failure to complete their task would lead to sudden death. Eventually, the entire class became playthings of the “underworld gatekeeper”