This Is a Disaster

Five years ago, a fog rose and enveloped a city. Everyone who tried to enter it to explore the secrets, no one came back, and panic spread throughout the world. Fortunately, the fog did not spread and only existed in that area. Except for the disappeared city, everything was as usual. In five years, that city was gradually forgotten. It wasn't until one day that the fog disappeared and the city appeared in front of humans again that humans knew that the world had begun to change.