A thick fog that has lasted for ten years has completely isolated Qingchuan City from the outside world. There are unknown dangers hidden in the fog, as well as the secrets of countless missing people. Lin Wu, a young girl, accidentally got involved in something strange in the fog while searching for her brother who disappeared three years ago. She meets Jiang Xun, a young man who also carries a secret. The two travel through abandoned neighborhoods, deserted hospitals, and old buildings swallowed by fog, getting closer to the truth step by step.
Thick fog is not a natural disaster, but a man-made situation. Memories are tampered with, identities are hidden, and everyone around you has a mask. When the fog dissipated, they discovered that the most terrifying thing was never the monster in the fog, but the darkness and lies deep in the heart. In this city where there is never a sunny day, only each other is the only light.
