Ainz Ooal Gown's Sorcerer Kingdom has claimed E-Rantel as its capital, but the city's merchants and citizens fear their undead ruler, choking trade across the region. Ainz sends his Floor Guardian Albedo on a diplomatic mission to restore confidence while he personally travels to the Dwarf Kingdom, drawn by their rune-crafting technology. Meanwhile, the Slane Theocracy and other powers begin plotting the Sorcerer Kingdom's downfall. This fourth season continues directly from Season 3.