When the First Contact War ended, Aiur had been conquered by the zerg Swarm. The protoss stood on the brink of oblivion, at risk of seeing their civilization disappear entirely. It was Artanis, a young executor, who prevented a bloody civil war and guided both the Khalai and Nerazim factions through the chaos of the Brood War. Now, with the Golden Armada at his command, he intends to take back Aiur and prepare his people for the final battle against an ancient and indomitable enemy.