A desert-dressed traveling priest of Serenrae visits the battle market of Kelmarane one year after the defeat of the Mouth of the Carrion King. He brings word of renewed gnoll activity and the reprecussions of the Carrion King. He advises the party to travel to the House of the Beast on the slopes of the Pale Mountain to slay the powerful gnoll before he can sweep down from the Brazen Peaks and wreak vengance on the village for slaying his vassal.
The group travels upriver for two days to the waiting house, surviving a river troll ambush on the way. They proceed quietly to the broken walls of the ancient structure dating back to the genie war several centuries ago. Karrd scouts ahead and in the largest intact surface structure finds a waiting group of guards and an imprisoned gargantuan scorpion. Working very quietly he releases the scorpion to the consternation of the guards and under cover of the ensuing chaos the party slips down the stairs to the underground complex of the house.
In their search for the Carrion King, they kill many gnolls and encounter countless desecrated human remains. They also find an insane surgeon who has twisted and perverted a sacred ritual of the goddess Lamashtu and used it to create hulking gnoll monstrosities, apparently degrading their intelligence in favor of bulking their mass and muscle.
The whole House of the Beast was constructed as a temple to Rovavgug the devourer and on a throne of twisted corpses and writhing maggots, the party confronts the Carrion King himself, a creature the size of the monstrous created gnolls, but clearly retaining his intelligence as well as his rage. The confrontation is a difficult one, several members of the party are nearly killed and are only saved by the quick actions of their companions. During the fight the Carrion King’s vizier takes no part but observes invisibly, when the King is finally brought down, this advisor is surprised by a glancing eldritch shot from Grant and vanishes through a wall.
In the quiet aftermath of the struggle, Karrd finds a lever beneath the Maggot Throne and reveals a descending stair winding deeper into the Pale Mountain.