Overview
The Lower Planes are referenced as the domain where the Sewn Sisters—a coven of night hags—originate and operate. They are described as “feared throughout the Lower Planes,” establishing their reputation as formidable entities before Acererak recruited them.
Connection to the Tomb
Acererak made a bargain with the Sewn Sisters specifically because of their Lower Planes origins and expertise. Seduced by the prospect of a near-endless supply of souls, the hags agreed to leave the Lower Planes and join Acererak in his tomb on Toril. They serve as nursemaids to the atropal, helping Acererak feed it necromantic energy through the Soulmonger device they helped craft.
Role in the Adventure
The Lower Planes serve as the original home of one of the tomb’s primary antagonist groups. The Sewn Sisters’ fearsome reputation across the Lower Planes underscores the danger they pose to the adventurers, as these are creatures that inspired fear even in their home plane of powerful evil entities.