The Invasion of Aiur is the ninth zerg mission of Episode II of StarCraft.



When Dark Prelate Zeratul killed the cerebrate Zasz, Zeratul's mind was temporarily linked to the Overmind's, and the Overmind learned from Zeratul the location of the protoss homeworld, Aiur.[1] The Overmind opened a rift in space and sent a bulk of its broods through it to begin an invasion of Aiur.[2]

As the zerg set down on Aiur, the Overmind tasked the Cerebrate with an objective that would allow it to manifest on Aiur. There was an khaydarin crystal formation behind a substantial protoss garrison, and the Overmind wished a shard of these crystals retrieved, as they had great power the protoss did not know of, and would be needed for the next phase of the invasion.[3]

The CrystalsEdit

The Cerebrate's brood engaged the Vanguard of Aiur, the protoss defense forces stationed around the crystal, and brought a drone to the formation to begin harvesting. The harvesting took a prolonged period of time, during which the protoss continued to assault the area. The Cerebrate defended the formation until the harvesting was complete, and then got the drone and the crystal shard it had taken to the safety of the hive cluster.[3]


The player's base is surrounded by cliffs with the entrance by ground to the east. Later in the mission, protoss air forces will attack from the cliff over the south. Throughout the mission, the three protoss forces present will only activate when the player moves their forces to certain locations. At first, only the Akilae Tribe is active, and the Velari and Auriga Tribes will do nothing. When the player moves near the Velari bases, or brings a unit south of the Akilae primary base, the Velari become active, and when the player's forces move near the Auriga bases or approach the khaydarin crystals, the Auriga become active. The player should keep this in mind and use this knowledge to avoid fighting too many enemy forces at once.

Once the player's base and economy are well established, the first priority should be to destroy the Akilae base far to the east and then south. The Akilae have a lone reaver, but otherwise their forces are limited to zealots and dragoons, and a swarm of zerglings and hydralisks can destroy them easily. With this done the player will have access to three expansion sites - the former Akilae base, a mineral field to the north, and another mineral field south-east of that, across the water. The player can claim these sites to continue expanding and upgrading their forces. The cliffs crossing the map host a number of photon cannons, and the player can consider using an air force to destroy them, but otherwise they are not a great problem, and destroying them may cause the player's forces to stray close enough to the Velari Tribe bases to awaken them.

When the player moves out of the mountains to the south, the Velari Tribe will become active. The player should use this time before moving further south to decide if they wish to destroy the Velari, or focus on holding the khaydarin crystal site. The former is recommended, as the Velari will periodically attack the player during the harvesting of the crystal. The player should build up a large force of zerglings, hydralisks, and mutalisks, being careful not to move too close to the Velari bases or too far south, to avoid activating them. The Velari bases are each protected by several reavers, so the player should send their mutalisks in first to destroy the reavers, then move in their ground forces and overwhelm the base. Once one Velari base is destroyed, the player can wipe out the other in the same manner.

With the Velari destroyed, the player can now move a drone to the khaydarin crystal. At this time the Auriga will activate and go on the offensive. The khaydarin crystal is surrounded by resources, providing incentive for the player to build hatcheries around it; the spread of creep in turn allows for the construction of sunken and spore colonies, which are ideal for helping fend off the Auriga tribe. The player should have overlords or queens with ensnare present, as the Auriga will send arbiters, cloaking their other forces until the arbiter is destroyed. The Auriga are the most powerful tribe and have access to the entire protoss tech tree, so the player should have a powerful garrison to repel them. Attacking the Auriga is not recommended - their base is heavily fortified on high ground with narrow choke points guarded by reavers, photon cannons, and archons. If the player does choose to attack them, an air force should be used.

It takes ten minutes for the khaydarin crystal to be harvested. When this is done the drone reappears with the crystal. The player must bring the drone back to their base to win the mission.

Starcraft - Zerg Mission 9 The Invasion of Aiur

Starcraft - Zerg Mission 9 The Invasion of Aiur


  • If the mission is extracted and viewed in the map editor, there is a humorous map description given to it - "Now that your here, the Overmind says you've got to do some wacky stuff before he can manifest himself."
  • In early builds of StarCraft: Ghost, data exists of this mission being playable, with the objectives "Find Khaydarin Crystal" and "Destroy Khaydarin Crystal." It is unknown if this was for testing purposes or was intended to be available in the final game.[4]


  1. Overmind: "Yet shall their overweening pride be their downfall. For when the assassin Zeratul murdered Zasz, his mind touched with mine, and all his secrets were made known to me. I have taken from his mind the secret location of Aiur, the Protoss Homeworld." StarCraft. Vivendi Games. Level/area: Eye for an Eye (in English). 1998.
  2. Blizzard Entertainment. StarCraft. Vivendi Games. Cinematic: The Warp (in English). 1998.
  3. 3.0 3.1 Blizzard Entertainment. StarCraft. Vivendi Games. Mission: The Invasion of Aiur (in English). 1998.
  4. 2014-18-12, StarCraft: Ghost Demo Build., accessed on 2020-02-16
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