Global warming has caused the Grod, a terrible ancient animal, to reawaken. Their relentless assault has led to a sharp drop in population and the dissolution of entire nations. Human society is in danger of disintegrating. The once-vibrant fields have turned into desert, toxic "Dead Soil" is visible everywhere, and mankind is in the worst danger ever. The surviving must evacuate to highland areas. In this game, Entropy, you will be going on a mission to reclaim your home.

The high-tech corporation "World Tree" Corporation started the "Returner Campaign" to help people take back their homes. In this campaign, the "Returners" will venture into the areas of dead soil that are populated by monsters like the one known as "Grod" in order to reclaim the earth.

The "Returners" are equipped with newly developed land purification devices and they started to go into the dead soil areas that are full of monsters, and you are one of them. 

The earth is a very dangerous place. The monsters are going to attack the "Returners" and are going to try to stop them from reclaiming the earth. The "Returners" are going to have to fight the monsters and defeat them in order to reclaim the earth.