This device aids travelers seeking the elemental planes of Fire, Air, Water, or Earth (or any of the para-elemental planes – obsidian, silt, magma… perhaps others, assuming you can catch rain or bottle the sun). The compass, a small urn carved of stone and containing hollow pockets, works only in the Ethereal plane, an inner plane, or the Prime Material plane (Athas).

To make the compass work, a representative sample of material from the plane sought must be placed in the urn and the lid sealed. Thus, to find the elemental plane of Fire, a small, burning fire must be place in the urn. Once sealed, the fire will burn until the lid is opened (just as water will not evaporate from the urn as long as the lid is sealed).
When used on an inner plane or the Ethereal plane, the urn glows yellow when the characters are heading in the direction of a portal of the elemental plane they seek. On an inner plane, the compass leads to the para- or quasi-elemental planar border that exists between planes. In the Ethereal plane, the urn leads to the Ethereal curtain of the desired plane. There are no range restrictions on the inner or Ethereal planes.

On the Prime Material plane, the compass glows when the characters are headed for elemental vortices of the correct element, provided the vortex is within range. The range on the Prime Material plane is 300 miles. This may also detect other portals that can reach the elemental plane being detected. It need not be active if a trigger is required, as long as it is a permanent entry or item.

The device was found near a clutch of eggs and the remains of a powerful kreen shaman. For some odd reason, she understands how it works… perhaps from ancestral memory? Could she be possessed?