Hundreds of thousands died when the first dungeon portals appeared on Earth.

Curiosity killed them.

Soon after that, the world changed. Ordinary people over the age of sixteen gained superhuman powers overnight. Reborn.

Ryan is a D-ranked support mage that clears dungeon portals with his friends to support his mother and sister. 

During one of their dungeon runs, Ryan and his friends are attacked by a man that is searching for something. 

Defeated and broken, Ryan fails to escape the dungeon before the portal closes, trapping him inside. Stranded, with no way to return to Earth, Ryan wanders the Labyrinth. A universe of interconnected dungeons, filled with riches and monsters.

Within the Labyrinth, he meets an unlikely ally that promises to give him the power to return to Earth. The power to grow stronger than he ever was. The power to avenge his friends.

But power comes with a price. And the Labyrinth does not forgive, nor forget.