Annoyed that Megumin had still been using his castle for explosion practice, Verdia, after proving easily susceptible to Aqua's purification magic, summons an undead army which is quickly defeated by Megumin's explosion magic.

Kazuma and Aqua visit a magic shop run by a kind-hearted lich named Wiz, who reveals herself to be one of the Devil King's generals in charge of protecting a barrier surrounding the Devil King's castle.