College student Linn accidentally traveled through time and woke up as a rat in a medieval sewer. Strange bodies and mysterious system tasks followed one after another. There was an army of hungry cockroaches chasing behind him, and the threat of hunting by human soldiers hovered above his head. And underneath this seemingly dirty and chaotic sewer, there are actually ancient prisons, mines, ruins of the dwarf empire, and even sealed ancient gods. In order to become a human again, Linn embarked on an adventure, but he didn't know that every step he took was uncovering the darkest secrets of the world.
