The Valethske had worshiped the Khorlthochloi as deities during a time when the latter commanded a vast galactic empire. However, through reasons unknown (and which were possibly simply natural to the Valethske in the first place) the vulpine beings began to act much too aggressive for the Khorlthochloi's tastes, possibly indicating that they were attacking the other races in the Khorlthochloi's care. Because of this, the great "deities" fashioned a plague specifically targeting Valethske, which nearly wiped out their entire race and thereby rendered them extinct in the wild. Those few Valethske who survived the purge proceeded to rebuild their culture and a number of their kind set out on the Great Mission, a centuries-long quest to find and destroy the Khorlthochloi; however it appears that they failed in their mission, as while their former gods did eventually go extinct it was their own technology that led to their demise.
Many theories about the Valthske were proposed by Professor Hamilton Smith.