The epic conclusion to the brilliant and hilarious fantasy adventures of Elliot, King of the Brownies. After accidentally waking the most evil demon of all time, Elliot's position in Underworld is being threatened.and there's a centaur hiding in his bathtub. Elliot's wintertime fun is interrupted with news that Jin the Yeti is coming for him, as a way to protect the Yeti from Kovol. Rumors about the Yeti spread around town, and plans are made to capture him. However, for Elliot's protection, a Centaur named Azure is called in to teach him magical self-defense. Worse still, Azure's highly emotional girlfriend, Calliope, needs to hide in a bathtub in Elliot's house. Elliot might be able to able to survive Azure's dangerous lessons, and maybe even the Yeti threat, but can he withstand the friendship of the neighbor girl, his arch-nemesis, Cami Wortson? As King of the Brownies, Elliot has battled Goblins, tricked Pixies, and trapped a Demon.

But now, that Demon has escaped and he's ready for revenge. Elliot will face a challenge unlike any he's seen before. The Last Underworld War is about to begin.