A new discovery in a previously mapped out dungeon might be the first step toward Kazuma repaying his massive debt. Unfortunately for him, Aqua is determined to help.

Kazuma is surprised to discover that Vanir had an extra life and has since quit his position as a commander to work at Wiz's shop, striking up a business partnership to sell products from Kazuma's world.

Evading the angry mob, the gang discover that the source of the town's water is being poisoned by the man from earlier, who is revealed to be one of the Devil King's army leaders, Hans the Deadly Poison Slime.