The party rejoins the Baron’s main army at its camp in the Red Maze, just across the river from the great city of the Black Pillar hobgoblins. They learn that the city’s population has been warped and driven mad by an attack using the terrible drug, Yellowspine. Cultists have already led away thousands of Warped Ones, but hundreds still occupy the ruins of the city. However, a force led by Blackleaf entered the city and contacted survivors- priests of Bane, who have negotiated a pact with the Baron, submitting the defeated citystate to the Baron’s control in exchange for their lives. Scouts return from various missions, reporting the great fields growing Yellowspine in the citystate of the Green Eye, and the blasphemous Warped One breeding pens in the citystate of the Red Whip.
Meanwhile, unaware of the truth about the fall of the Black Pillar and the corruption of the Green Eye and Red Whip, a vanguard from the citystate of the Spined Crown approaches. The party determines to convince them of the true threat and enlist them against the Cult of Those Who Hear, which now rules the Green Eye and Red Whip. To do this, they plan to cleanse the city of the Black Pillar, secure Warped One specimens to present to the Spined Crown hobgoblins, and obtain powerful magic and weapons that might still remain in the city, which was constructed upon the site of an anciet tiefling city during the height of the diabolical empire of Bael Turath.
The party initiates a complex plan to assault the city, isolate the Warped Ones in the various districts, rally with the priests of Bane, and eventually clear the city. It is a race against time as the party moves to trap the hordes of Warped Ones in the Slave Market before they can swarm out into the middle district and overrun the Baron’s army.