Seven strangers, each with their own secrets, were sent to the "Wuzhishan Mental Hospital" by an anonymous invitation to participate in a closed experiment. Those who completed the experiment were promised huge bonuses and the opportunity to "restart their lives." The project leader "Tang Xuan" who leads the team seems gentle, but always issues strange instructions late at night; "Sun Kong", a former criminal police officer, is unruly and always wears a pair of special gloves on his left hand, which is said to hide wounds that cannot be healed; "Zhu Wu", a retired female soldier, has a burly figure , but always murmurs to his own reflection in front of the mirror; the taciturn "Sha Jing" carries a heavy black backpack and never leaves his body; and there are three unidentified participants who were targeted by an invisible force the moment they entered the mental hospital.
As the experiment progresses, strange events occur one after another: children laugh in the corridor at midnight, distorted figures appear in the mirror, and everyone's nightmare begins to play out in reality. They discovered that the layout of this mental hospital completely overlapped with the road map in a lost ancient book, "The Western Regions of the Tang Dynasty", and that the so-called "experiment" was nothing more than an ancient ritual of sacrificing life. When they tried to escape, they realized that they had already become sacrifices on the "Night Journey West". If they want to survive, they must uncover each other's secrets and fight against the "gatekeepers" who awaken from the darkness - and the source of all this points to a covered-up tragedy in the hospital fifty years ago.
