Dark Origin is a secret mission in StarCraft Episode VI. To access it, the player must complete the previous mission, The Reckoning, with 5 minutes or more left on the timer. It cannot be accessed directly with the level skipping cheat.
In the aftermath of Zeratul's last battle with Sarah Kerrigan, Matriarch Raszagal lay dead, and the protoss forces Zeratul brought with him to Char were in disarray. Kerrigan allowed Zeratul to leave Char with a small force of survivors, and they set course to Shakuras.
En route to the planet, one of Zeratul's allies, a high templar, detected protoss energy signatures on a nearby uncharted moon. Records did not indicate that any protoss settlements have ever been founded on that moon. Zeratul believed it may be Artanis or other protoss survivors, and directed his course towards the "dark moon".
The Dark MoonEdit
Zeratul took a small force with him: a pair of dragoons and four dark archons. The high templar warned Zeratul that a terran compound had been detected nearby. Zeratul acknowledged this and decided to investigate. Zeratul and his allies fought their way past hostile mercenaries, and found a stasis cell, surrounded by pylons. The cell contained a protoss being monitored by the cell, and the cell shortly exploded when the pylons went critical.
Zeratul continued to explore the area, encountering more stasis cells and pylons guarded by mercenary forces. Some of the tanks held protoss, others held zerg, but each had their psionic emanations and DNA codes monitored. Zeratul eventually reached a cell with a zergling. The computer said that gene splicing had been completed between subjects twenty-five, a protoss high templar, and twenty-seven, the zergling, and that Experiment 2273 was progressing. Zeratul was horrified.
Test Subject Twenty-NineEdit
In the most heavily guarded area of the facility, Zeratul found a creature unlike any he had seen. The computer informed him it was "test subject twenty nine" and declared it was a protoss/zerg hybrid. The hybrid was in perfect cryo-hibernation and its psionic emanations were minimal.
At this time, a mysterious voice contacted Zeratul. The voice announced itself as Samir Duran, but said it had taken on many names "throughout the millennia" and Samir Duran was only how Zeratul would know it. It denied Kerrigan having any hand in the experiments here, and Zeratul questioned what Duran was if not her ally. Duran said he was a servant of "a far greater power" that had slept for "countless ages" and was reflected in the hybrid.
Zeratul declared the hybrid an abomination, and Duran mocked his violence and inability to understand what he was doing. He told Zeratul he could destroy all the test subjects at the facility, it would do no good; he had seeded hybrids on many worlds, and Zeratul would not find them all before they awakened, and changed the universe.
Zeratul destroyed the hybrid and the entire facility before leaving the moon. He was unable to explain the discovery to his companions, but knew the hybrid did not bode well for the future. He subsequently traveled the stars for the next four years, looking for clues to what Duran had told him about.
Careful micromanagement of the dark archons and other forces is essential to this mission. To the east are three marines with two siege tanks. Kill the marines with Zeratul and use dark archons to swiftly mind control the two tanks. A science vessel will come to investigate and should also be mind controlled. Beyond this more marines guard a missile turret, and the first stasis cell to find is nearby.
At any time during this next paragraph, a dropship with some combination of medics and ghosts will fly in; it should be mind controlled before it disembarks these units, to take control of them as well. To the south on a cliff is a siege tank to take control of. The three siege tanks can then assault a row of pylons and photon cannons to the east. A battlecruiser in the area will move in to attack as the garrison falls, and should also be mind controlled. With the defenders gone there is another stasis cell to find behind the row of cannons. Destroy the cell after Zeratul examines it to release a high templar.
To the west is a cell guarded by several marines. Killing all the marines destroys the cell and spawns an infested terran; if the cell is destroyed before killing the marines, it will still spawn in the cell's previous location. On a cliff beyond this point is a stasis cell that can be destroyed to release an archon. There is also an SCV to mind control here, and it comes with a few resources to allow for repairs. Further west a science vessel patrols between walls with marines stationed on them. A dark archon can use feedback to kill the vessel, and then the player's own vessel can spot the marines on the high ground for their siege tanks to kill. Bring Zeratul to the cell, then destroy it to release three zerglings and another high templar.
To the east are a group of firebats, and then the final part of the level. Several wraiths are patrolling, kill them with a dark archon's feedback. Several siege tanks and a battlecruiser wait behind them. Use the science vessel's defensive matrix on a unit and send it in to bait the battlecruiser away, then mind control it. Use it and the previous battlecruiser to destroy the tanks. More battlecruisers may respond to the attack, mind control them as well; there are three total around this part of the facility. The battlecruisers and siege tanks can now break down the bunkers defending the facility and all other defenders within. Ghosts may come to lockdown the units, but the previously mind controlled medics can restore them. When the way is clear, bring Zeratul to the beacon to finish the level.
There are three ursadons roaming the map. If all three are killed, the last contains a broodling in its stomach. Broodlings normally die after about two minutes of life, but this broodling sticks around. This is likely because there is currently no way to set the broodling's self-destruct property using the StarCraft editor function used to spawn it in this mission. Only broodlings created specifically with the queen's "Spawn Broodling" ability die when they run out of energy.
There is a disabled transmission in the map, where Zeratul is surprised to see pylons at the first stasis cell, and comments that no terran mind could comprehend the energies of pylons or figure out how to utilize them to power a stasis cell.
There is a hidden sound file within the map (which can only be accessed by extracting the map). In it, Fenix says "how do you terrans say it? Getting jiggy with it", a reference to a similar remark he made to Jim Raynor while on Moria.
StarCraft: Brood War. Vivendi Games. Mission: Dark Origin (in English). 1998.