The Ethereal Plane of Atrii, home of the Implementors reigning over Zork, is one of at least two alternate planes of existence which is an extension of the Outer Halls. Parallel to the universe in which the planet of Zork resides, the plane has specific locations that coincide with the same locations in the real world. However, the geometry and very nature of space in the Ethereal Plane is different in an indescribable way. The landscape, and even thunderclouds, are compressed into a flat optical plane, stretching away below one's feet in every direction. Occassionally, routes of travel are blocked by vague outlines, stretched tightly across the path, which can only be defeated by ethereal weapons, such as a phase blade.

Those who have mastered transcendental physics can easily jump back and forth from the Ethereal Plane to the real world via magic curtains called Dimension Doors, or through the use of a Scroll of Gating. These transcendental voyagers report that solid objects from the Ethereal Plane appear only as vague outlines in our world, and vice versa. Due to this method of transportation, this parallel dimension has became a home of sorcerers, which they shared with snack-cakes, former child stars, and people who own ferrets. In 966 GUE Orkan of Thriff was so easily able to transport his entire village in this manner anywhere he desired in our world.

G.U.E. Tech resides in the Ethereal Plane, but has at least two entrances to the physical plane. The Ye Olde Magick Shoppe chain was also linked to each other through Dimension Doors.

The Happy Fields where Joy forever dwells, is one of the homes of the Implementors on this Plane which is filled with harmonious and estatic cherubim and seraphim.