The Children of Kings

Although the Terran Federation has departed Darkover due to a nasty interstellar civil war, the planet's location in the galactic arm makes it a prime hideout for smugglers, rebels, and other refugees. When smugglers start arming the warlike Dry Towners with forbidden weapons, Gareth Elhalyn, grandson of Regis Hastur and heir to the throne, takes off on a secret mission to stop them...