Jack, a newcomer in the workplace, is tall and powerful, starting his career at a design company on the fifth floor of the building. Frequent elevator malfunctions confuse him. As the author, I initially guided the story and had an ambiguous relationship with a female character, but in order to wait for the true female lead, I chose to restrain myself. The current female lead is Lucy, a stunning 30-year-old manager who needs protection. On the fifth floor of the building, there is a demon named Xiao Li, who is possessed by a black cat to retaliate against the boss and female manager. The black cat in the nearby funeral home is also a demon, seeing the boss as an enemy. Jack, the gatekeeper, and Lucy bravely fought and temporarily suppressed the demon. We need to find a new owner of the Wuzi Tianshu to eliminate the demon, but the new owner only appears 50 years later. The story showcases revenge, faith, and courage, exploring human nature and destiny. Jack will grow into a demon-slaying hero, and his relationship with Lucy is also exciting.