The heroes travel to the Abyssal town of Broken Reach to consult with Red Shroud and secure a route to the Wells of Darkness, which leads them to the Well of Arlgolcheir, the prison of a fallen demon lord. They soon discover Shami-Amourae's well, where she refuses to help them until they free her. But the only way to free a demon lord from the Wells of Darkness is via the demon lord who created the prison in the first place.
This demon is Ahazu the Seizer, and his well can be found below the fortress of Overlook. After defeating the fortress' guardians, the heroes negotiate with Ahazu the Seizer to secure Shami-Amourae's release. Yet when they return to the Well of Debased Eros, a contingency put in place by the Prince of Demons opens a planar breach in the depths of the River Stix, diverting the legendary river into the well and unleashing a demonic assault on those who seek the forbidden knowledge. By rescuing Shami-Amourae from this assault, they can finally learn the truth about what Demogorgon intends to do with the harvested energy of the savage tide.