To obtain a detection artifact to find the enemy of a friend.Wade, an adventurer specializing in labyrinths, comes to the dungeon. He entered the dungeon with an exploration party led by a nobleman.A giant dragon blocks their way and the exploration team is wiped out... Wade fights the dragon with determination, but is unable to overcome it and is fatally injured.However, when he woke up, his wounds had completely healed and he had become a dungeon master...!? The labyrinth defense tale of an adventurer trapped in a dungeon begins!!!