In the Homeworl series the Guidestone served as a catalyst for the Exiles to return to their homeworld. A historical relic, it displayed a map of the galaxy with precise co-ordinates leading towards the original homeworld of the Exiles. It was discovered in the wreck of the Khar-Toba on Kharak and started the chain of events leading to the Homeworld Wars and return of the Exiles. The Guidestone was made of rock taken from the Angel Moon, Hiigara's only moon.