In AD 2149, an unforeseen "grey fog" swept across the world. It was not a meteorite impact, nuclear war or artificial intelligence rebellion (different from the traditional apocalypse), but an unknown, non-material "grey fog energy" that penetrated the atmosphere and covered the entire earth's surface. Gray fog is not a deadly poison, but it can distort biological genes, corrode consciousness, blur spatial boundaries, and give birth to "fog aberrations" (non-zombie, non-mechanical, genetically distorted animals and plants + consciousness remnants). At the same time, the world's electrical and electronic equipment completely fails, returning to the "low-tech survival era" - no network, no large machinery, and can only survive by relying on primitive tools, simple modification equipment and a few "gloomy items" that can resist the erosion of gray fog.
Gray fog has obvious "concentration stratification": shallow fog area (the gray fog is thin, visibility is 5-10 meters, the aberrations are weak, humans can move for short periods of time, and is the main living area), medium fog area (the gray fog is thick, the visibility is less than 3 meters, the aberrations are medium in strength, and there are a small number of "Fog miasma", inhaling too much will cause confusion and can only be explored briefly), deep fog area (the gray fog is as black as ink, the visibility is 0, the aberrations are powerful, there are "space folds", almost no one who enters survives, it is rumored that the secret of the gray fog is hidden deep in the depths).
