The planet Darkover was originally a human colony that lost contact with Earth. The colonists crossbred with Aliens, already on the planet, which their children inhereted the ability of 'Laran'. Those with strong ability are marked by having red hair. The ability can be amplified by using Matrix stones, which are blue jewells. Once the Terran Empire rediscover Darkover it becomes important as a stopover point for Terran Starships travelling the Empire. An epic series that covers the discovery of Darkover, by the colonists, to the destruction by the Terran Empire.