Garan’s Valley had originally been a shallow, D-class Dungeon with ten floors. However, perhaps because it had been abandoned for over two hundred years, there were three more floors.

That was why a mid-boss had appeared here.

Dungeons with eleven or more floors spawn mid-bosses. They appear roughly every ten floors, and they are known as mid-bosses because they are stronger than regular monsters but not as powerful as bosses.

For example, a Dungeon with twenty-seven floors would have a mid-boss appearing on the tenth and twentieth floors, and then a boss on the twenty-seventh floor.

It is common for an adventurer party in the midst of clearing a Dungeon that has never been cleared yet defeating a powerful enemy and thinking,「This was definitely the boss of this Dungeon」, only to discover a staircase leading further down instead of a treasure storage chamber, revealing that the powerful enemy they defeated was merely a mid-boss.