An Atmosphere Of Angels by H. C. Turk

In the 23rd century, Earth has achieved interstellar travel. The greatest find is a planet with deposits of ether ore: a mineral required for journeying across the ether lanes. Since the ore is protected by an indigenous race, Terrans must barter for the material as supervised by Earth Nations United.

Parno Hadjara is the chief anthropologist of the staff that journeys to Kapnos 3. Kathlynn Shumard is the ENU supervisor. Soon after landing, Parno and Kathlynn approach the indigenes. Though the two are adversaries, they are drawn to one another.

The indigenes soon begin a mass ritual filled with sex, violence, and voodoo. The rite reveals the location of an abandoned space vessel surpassing Earth technology. The indigenes offer the Terrans a bargain: Remove this vessel from our land, and the ether ore is yours.

The entry to the ship will open briefly. Parno rushes to the site and enters, followed by Kathlynn, and the entry closes. The Terrans are trapped in a huge ship whose crew was murdered. The one alien remaining is a ghost who can only achieve peace by killing Parno and Kathlynn.

In order to escape, the Terrans must learn the workings of the ship. The ghost tries to kill them via spontaneous combustion, offworld narcotics, drowning in alien viscera, high-tech disintegration, and common beatings. Though severely injured, Parno and Kathlynn are healed by the ship.

When the entire ship begins disintegrating, Parno and Kathlynn are forced to face the ghost. If they succeed, the ether ore is theirs. If they fail, they and the ghost will achieve unending peace.