Overlord, Vol. 11 (light novel)

In search of the lost art of rune crafting, Ainz journeys to the land of the dwarves. Accompanied by Aura and Shalltear, he arrives only to find that the Dwarven Kingdom is beset by an invasion run by someone besides himself. He soon strikes a deal to obtain the secrets behind the making of runes in return for assisting the natives in reclaiming their capital.