A deep chasm contains a well- hidden realm sheltered from the ever-present acidic snow. Built of equal pans basaltic rock and giant bones is a rough castle. The castle is scaled to the proportions of its master, an outcast fire giant wizard named Tastuo. Her eight siblings, fellow outcasts, also reside in the castle. Like their sister, all are either wizards or sorcerers.

Yugoloths of the layer have several interlocking contracts with Tastuo, which helps ensure the valley's safety should her enemies ever find her. Tastuo never names those enemies, but her predicament makes her sympathetic to the plight of travelers seeking asylum. Thus, the Valley of the Outcast doubles as a way station for visitors in need, but only if they can find it.