Arty leads Bariq, Jhank, and Render to Highstar Lake, where they search for the underwater bubble they glimpsed many months ago. They find an enormous bubble protected by arcane traps and considered to be the property of Sh'derra D'zeer, the amethyst dragon who claims the lakebed as her own. They go to investigate rumors that the Wererats of the Hark are building canals and stop to attack a depressed hill giant along the way.