When the war between the aboveground and underground ended, humanity was joined by so-called "dungeon babies," those gifted with supernatural abilities and an obsession with the labyrinths below ground. Despite being a dungeon baby, Kim Jin-U suppressed his instincts, choosing to live an ordinary life as a guide and caring for his family. But when an expedition goes wrong and he somehow ends up becoming the new owner of a labyrinth, he discovers that he cannot ignore his instincts forever...