Mildew and Mist City

An unknown mutant fungus broke out from the virgin forest area in the south and swept the world. The fungus releases a large number of gray-brown spores visible to the naked eye, which spread into a thick fog-like "gray mold tide". Fungal activity is strictly controlled by temperature: when the temperature drops at night, spore activity surges, spreading wildly with the wind; when the temperature rises during the day, spore activity is suppressed by high temperatures, and a large number of spores settle on the surface, leaving a short breathing window for survivors. **