Someone in the Wall

When the protagonist, Cao Deyou, discovers that his friend Paigu has mysteriously vanished, he joins forces with his other friends to investigate. But the investigation brings one hardship and accident after another. Desperate to uncover the truth, Cao Deyou humbles himself and becomes an apprentice to the exorcist Liu A Gong. After completing a series of lessons, he returns to investigate the old mansion. There, he and his companions encounter even more terrifying events. His soul becomes lost in the dark space created by the mansion, unable to return. Faced with this haunted realm, what will Cao Deyou do?