The mission on Mustafar saw an unidentified spacer collaborate with Jedi Master Obi-Wan Kenobi's spirit in order to correct an imbalance in the Force on Mustafar. The mission saw Kenobi task the spacer to find a shard and remove its influence in order to correct the imbalance and remove the dark side's influence on the planet. The spacer located it and attempted to return it to it's chamber but had to confront the Dark Jedi Vartonis and his hired Brotherhood Mortalis members. The spacer eliminated them and succeeded in correcting the imbalance for Kenobi.
Millennia prior on Mustafar, events caused a major disturbance in the Force that empowered the dark side on its surface. The Jedi Order at one point in previous millennia had a chapter on the planet and the Jedi uncovered a large crystal of unknown origin; the Jedi learnt that it attuned to the Force within them individually. However, news of an impending Sith invasion prompted them to experiment on the crystal, hoping that it could help defend the chapter. The Jedi believed that channeling their powers through the crystal could strengthen their abilities, while significantly diminishing those of the Sith. However, while this worked at first, the crystal slowly began cracking as the power within it was being pushed to the limits.
The crystal exploded and sent the planet out of orbit, while it killed all Jedi and Sith save for the remaining elder Jedi Master Erg Krow. As the crystal exploded, he managed to shield himself from some of the ensuing destruction, and though injured, found a large shard of the crystal still remained relatively intact. Krow went into hiding with the shard, spending the last ounces of power he had left to use the Force to put a protective shield around it to make sure that other Force-sensitive's could not sense its presence. Krow succumbed to his injuries shortly after, and the shield he put in place gradually diminished after a few millennia.
Over time, however, rumors persisted about tales of ancient treasure; this drew intrepid adventurers to Mustafar in search of such treasures. But rumors about the crystal drew darksiders to Mustafar, including the Dark Jedi Vartonis who hired the Brotherhood Mortalis to aid him in securing the shard so he could intensify his power in the dark side of the Force.
Jedi Master Obi-Wan Kenobi - months after his death on the first Death Star - visited Mustafar as a spirit to investigate how to eliminate the evil presence on Mustafar and correct the imbalance that existed. He approached an unidentified spacer and secured their assistance since he himself was unable to do so. He warned the spacer that the dark side was growing in strength and that failing to correct the imbalance would further empower the dark side more than it already was.
Kenobi told the spacer that the shard that remained had the active soul of Jedi imprisoned within it; he was certain that this shard could be used to gain entry into Krow's chamber. Kenobi asked the spacer that the shard be recovered so that it could be destroyed, so as to prevent the dark siders from claiming it as their own.
The spacer found the shard in the possession of a crazed Mustafarian hermit, and the fact that his movements were erratic made it difficult for even Kenobi to locate him through the Force. The Jedi soul, according to Kenobi, was in great pain and he mused that the spirit may have been what gradually drove the hermit insane. While the spacer merely wanted the shard, the hermit grew hostile, and was killed in the ensuing confrontation. While Kenobi expressed regret at the hermit's death, the spacer was adamant that it was an unavoidable confrontation, which Kenobi conceded.
Both Kenobi and the spacer managed to locate the Lair of the Crystal and Kenobi sent the spacer ahead to locate it while he used his abilities to delay the dark siders who were hunting the crystal down. The chamber was located north of the central volcano in a place called the Burning Plans, and was located in its north-eastern corner. When the spacer arrived, Kenobi's spirit returned. Inside the inner chamber, Vartonis and the Brotherhood Mortalis members arrived, hoping to lay claim to the crystal shard. The spacer confronted them, successfully defeating them.
The spacer's actions helped to correct the imbalance on Mustafar by destroying the shard and thereby ridding its influence on the planet for good; Kenobi expressed his gratitude to the spacer before departing.
- Star Wars Galaxies: The Complete Guide: Prima Official Game Guide
- The Essential Atlas