After retrieving the Uraj from the surface of Braxis, the protoss traveled to Char to retrieve its twin crystal, the Khalis. Char was still under the control of Daggoth's Renegade Swarm, and the second Overmind had nested near the Khalis. Though there were numerous zerg defenders, Sarah Kerrigan believed a strike force could break through them and retrieve the crystal. Praetor Artanis instead suggested an assault on the Overmind, doing enough superficial damage to send it into remission and temporarily pacifying the zerg.
As the protoss established a base camp, Kerrigan took control of a nearby brood, allowing them to reinforce their numbers with zerg. Together, the two combined armies were able to hold off the hostile zerg long enough to retrieve the Khalis and escape the planet. With both crystals secured, the protoss and Kerrigan returned to Shakuras.
The most significant gameplay change in this mission is that the player receives control of a zerg base. The player has access to the zerg tech tree up to a lair and associated units and upgrades, with the sole exception of being unable to mutate lurkers. The zerg base is the only one with a vespene geyser, so the player should quickly build an extractor there and begin mining. Note that probes and drones can gather gas from either an assimilator or extractor, and can return resources to either a nexus or hatchery. If the player needs more gas, there is a small mineral field with a second geyser south of the zerg base.
Once the player's economy is established, they can begin deciding which of the two objectives they wish to pursue.
Retrieve the KhalisEdit
The area around the Khalis is full of spore colonies and scourge, so the player will need to move in on foot. The path to the Khalis contains numerous sunken colonies and zerg defenders. Without their adrenal gland upgrade, the player's zerglings will not be at their full power, so the player should focus on zealots as their attack forces, and supplement them with dragoons or hydralisks. The player should also have some reavers to handle masses of zerg and destroy the sunken colonies out of their range. This mixed force can fight their way through the zerg to the Khalis, ending the mission when a probe or drone is in its radius.
Assault the OvermindEdit
The Overmind is nested below an unguarded cliff, allowing an air force to slip past most of the defenders. There is a zerg base to the west the player should destroy as soon as they are able, and claim it their own with several hatcheries. At their main base the player should build stargates and warp in carriers, at least eight, and supplement them with mutalisks, as many as the player can muster. Both should have their weapons and armor well upgraded. This force can fly far south along the western edge of the map to reach the Overmind. While the player's mutalisks engage the zerg as a distraction, the carriers can focus their fire on the Overmind to defeat it and end the mission.
Alternate Ground-Assault Strategy Edit
An easy way to win via the Overmind victory is to go full ground and swarm it.
At the start of the mission, immediately move one drone south of the zerg base along with all your protoss units except Dark Templars. Mine and build Drones/Probes, spend gas on Protoss Ground Attack and Zergling Speed + Melee 1. Move your two Dark Templar west along with the Observer and kill the two Lurkers, preferably walking around them first as they will try to unburrow. Kill both and an Overlord will arrive so retreat. The drone sent south should make a hatchery next to the gas. There should be 2 drones and probes per mineral patch. Gas should be built at the new expansion and once built, saturate the mineral line with 5-6 drones and in the next few minutes have 4 more make 3 sunken colonies and 1-2 spore colonies just south of the new hatchery, so you can relieve your starting protoss units of defense duty eventually. Spend your scarce gas on Protoss tech upgrades, Lair, Protoss Forge tech, Zealot legs, Singularity, and the occasional photon cannon and pylon along the southern shore, which will be attacked by Zerg air and drops. Anytime you float more than 600 minerals, add a zealot or 12 Zerglings. If you float more than 200 gas and are finished/researching the Protoss tech you need, add a Dragoon.Once you have 2 control groups (24 units) of Protoss, several overlords and observers, and 2 control groups of Zerglings (with speed and Attack 1/2), swarm the west expansion. Use Zerglings as cannon fodder first and attack move in. Make sure some observers and overlords are following in as Lurkers may burrow in the base. The Zerg have enormous amounts of Spore colonies so air upgrades and units are not preferable beyond Protoss attack 1 or 2 along with corsairs to kill any guardians that might attack (and be too far across the water to hit with ground fire). Build a hatchery, preferably up to 3, at the new expansion and saturate with drones or probes rallied here. Make sure 2-3 forges are continually upgrading ground attack, zerg melee is being upgraded too (carapace is overkill given Zerglings are more of a distraction here). If you have thousands in minerals, add new hatcheries at your old bases and rally point them to the western corner, and continually make zerglings. With 4 bases mining and 4+ hatcheries, several gateways, it's easy to get 2-4 control groups of protoss with 2+ upgrade levels as your core attack, and endless swarms of expendable zerglings to support. With this swarm, attack-move across the map. Zerglings will flow through the canyons like a river, overwhelming the enemy. Ultralisks will not go down easy to zerglings so have your protoss units focus them and dragoons focus any air attackers or lurkers. Your river of zerglings should be flowing through and killing sunken colonies and half should go straight for the overmind, with a control group of Dragoons/Zealots in tow. Zerglings will distract and let the Protoss units focus down the overmind while the Zerglings die and absorb Sunken colony hits. Other Protoss units can finish off buildings in the mean time and soon the Overmind will be worn down.