Middle School Mystery: the Theory of Separation of the Undead

Tragedies of students jumping off buildings occurred frequently in a middle school in City Z, and five junior high school students were unfortunately involved. They sneaked into the school's unfinished teaching building construction site at night, and encountered many dangerous and incredible things inside. They finally escaped from danger, but they were involved in a greater crisis... Seven years later, they made an appointment to visit the construction site of the middle school again. At this time, it had become the place where the teaching building was completed. It was the school library. They encountered danger again... What is the truth behind the student jumping off the building? Who is the murderer behind the supernatural phenomena? Can they return safely this time? This is all a mystery... This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.