Deathmoon was a moon of the planet Fyodos. It had another name prior to the Great Cleansing, but it was lost to the Fyodoi. When the Deathmoon was full in the skies of Fyodos, the Fyodoi became fearful as the satellite resembled the withered face of a corpse.
Prior to the Great Cleansing, the Deathmoon was the location of a military base staffed by up to twenty-four personnel, along with hundreds of atomic missiles. During the war that decimated the planet, the base was ordered to fire the missiles, but the personnel refused to do so. The personnel, abandoned the station, either returning to Fyodos to die, or striking out for other planets.
The base was linked to the Tharak installation on the continent of Tharak; energy pulses were sent between the installations at eight-hour intervals which counted down a six month "doomsday clock." If the timer was ever to reach zero, the atomic missiles on Deathmoon would be automatically launched. The shaman of the Roh tribe unwittingly resets the countdown every six months through a pilgrimage to the Tharak installation where they follow a series of commands in pushing buttons and pulling levers.