"Blackthorne" is set on the planet Tuul, which has existed for centuries without human knowledge. All of this time, Tuul's people have been ruled over by a single shaman who "was blessed with all knowledge". Years before the game begins, Thoros, the latest ruler, finds it near impossible to choose between his two sons as the next ruler. Believing it will solve the dilemma, he leads them to the deserts and kills himself. His body becomes two stones, light and dark, and he gives one to each boy to rule their own kingdoms respectively. The people of the lightstone form the kingdom of Androth, and the people of the darkstone form Ka'dra'suul. But while Androth respects their stone, Ka'dra'suul reject theirs, and are eventually transformed into monsters by it. In this time, a ka'dra named Sarlac seizes power. He forms an army and leads them against Androth. Knowing of his people's doom, the ruler of Androth, King Vlaros, with the aid of the Androthi magician Galadril, sends his son Kyle to Earth to save his life. Vlaros also gives Kyle the lightstone for safe keeping.