VR game designer Ling Jiushi, frustrated with his work, decides to resign. However, a beta test game provides him solace and distraction. Unexpectedly, he receives a game disc from overseas. Following an accident, he finds himself in a corridor with twelve iron doors. Inside one door of this strange place, a mysterious figure helps Ling Jiushi escape from the perils of the snowy mountains, welcoming him to the world beyond the doors. Within the doors lie grave dangers where a single misstep could cost him his life. Ling Jiushi soon discovers a chilling truth: peril encountered within the doors can also affect him in the outside world, making his journey through this mysterious realm even more treacherous.