Kizrath began the Aridas mission by explaining to an Executor the importance of the Argus Stone. Kizrath said it was thought to be located in the fabled city of Taledon, and his observers had discovered what may have been Taledonian ruins on the planet.
Kizrath ordered his troops to attack the Aridian terran forces from "defiling" the ruins. He discovered that the ruins were only a conduit to a larger set of ruins, from which he could detect psionic emanations from xel'naga relics.
Kizrath personally led the Protoss Crusaders for the Stone against terran forces which had occupied Taledon. The Argus Stone sat in a temple, which had to be destroyed so Kizrath could acquire the Stone. The terrans were defeated in the battle.
Kizrath's good luck did not hold, however. He ordered his forces to retreat from Aridas, clearing away zerg attackers to do so and gaining the assistance of an escort of carriers and an Escort Leader. However, at the evacuation point, he was met by the Escort, whose commander told him that the protoss government believed the Argus Stone held little value in the war. Kizrath was ordered to remain on Aridas, where he would study the Stone.