During the zerg invasion of Tarsonis, the Overmind, the leader of the Zerg Swarm, found a creature that had the potential to become the Overmind's most powerful agent. This creature was encased in a chrysalis that would deeply infest it and transform it into a zerg. To safeguard the chrysalis during its incubation, the Overmind created a new Cerebrate with the sole purpose of protecting the chrysalis. The Overmind tasked its other cerebrates Daggoth and Zasz to instruct and train the new Cerebrate in the ways of the zerg.
Daggoth tutored the new Cerebrate in how the zerg expand and mutate their forces, while Zasz scouted the area. He found remnants of Confederate Omega Squadron nearby, and tasked the new Cerebrate to destroy them to ensure the chrysalis' continued safety. The cerebrate did so, sparing no one.
The Overmind was pleased with the efficiency and dedication its new Cerebrate showed in pursuing its objectives, and continued to entrust it with the protection of the chrysalis, promising it that their power would grow in tandem.
The mission is a tutorial level that teaches basic zerg gameplay, which is significantly different from the terrans. The first stage is a walkthrough of basic base building: training drones and overlords, and building a spawning pool which unlocks zerglings. Once the spawning pool is complete, destroying the nearby terran base becomes the objective. The terran base will becomes active after 3 minutes of gameplay.
Starting forces are sufficient to destroy the terran attacks. Build a second hatchery to increase unit production. Train two dozen zerglings with hydralisks, and upgrade them fully; these are sufficient to destroy the terrans. Hydralisks are needed to deal with enemy wraiths. There is a starport on the raised ground to the west of the terran base. Destroy all enemy structures to complete the mission. If the player destroys all enemy structures without building a spawning pool and a hydralisk den, the mission won't be completed until the player builds them.
- ↑ 1.0 1.1 Blizzard Entertainment. StarCraft. Vivendi Games. Mission: Among the Ruins (in English). 1998.
- ↑ Blizzard Entertainment. StarCraft. Vivendi Games. Mission: Egression (in English). 1998.