Underground Wizardry

Immortals may not be in the sky, or they may be underground. For Zhang Zhen, who accidentally traveled through time, this world is indeed like this. At least the human immortals were really underground and were beaten down. Is there still a chance to return to the ground? I don't know, let's survive in this miserable place with my junior brothers and sisters first! Originally, he was just an unemployed young man preparing to take the civil service examination. How could he become like this...