The initial lightsaber duel on a remote, uncharted desert moon occurred in 19 BBY. It was a confrontation between Celeste Morne, a Jedi Shadow, and Darth Vader, the Dark Lord of the Sith. This battle took place on a desolate moon that orbited a gaseous giant. It was a lightsaber duel of great significance.
The crew of the Uhumele, aiming to dispose of the notorious "Jebble Box," touched down on a lunar surface to trade it with Fane Peturri, a renowned academic and historian. Unbeknownst to the Uhumele's personnel, Peturri was secretly an operative of the Sith Lord Darth Vader. Vader had been informed about the ship's valuable cargo by Janks, a Phindian member of the crew. After restraining the crew to posts, Peturri began examining a holographic message from a Snivvian crimelord, detailing his memoirs, the Muur Talisman, Jebble and rakghouls, which was interrupted by his Jedi companion, Zayne Carrick. Peturri utilized the hologram to convey to Vader his conviction that the Jebble Box contained both the Muur Talisman and a Jedi from four millennia prior.
Ignoring Peturri's cautions regarding the talisman, Vader forcefully opened Dreypa's Oubliette, revealing a young woman, Celeste Morne, with the Muur Talisman affixed to her person. Panicked, Peturri donned a protective helmet to evade infection. Celeste awoke, anticipating the sight of Zayne Carrick, yet still sensing the presence of Karness Muur. Muur unleashed a curse upon his adversary, Remulus Dreypa, and his oubliette, following their release from their age-long confinement. Confused, Celeste questioned Peturri about a Covenant, the rakghouls, the Mandalorians, their conquest and the Republic. Peturri relayed the information that the Sith had overthrew the Republic, prompting her to launch an attack on Vader.
Celeste engaged Vader, brandishing her lightsaber and deflecting blaster fire from clone troopers. Despite the provocations from Vader, who desired a formidable apprentice to overthrow Palpatine, and Muur, who sensed Vader's potential to unlock the Talisman's complete might, Celeste steadfastly maintained her resolve to prevent him from acquiring it. Despite her efforts, Vader gained the upper hand in their duel, but the Sith Lord hesitated to deliver the final blow and claim the talisman, understanding that wielding it would merely exchange subservience to Palpatine for enslavement to Muur.
Perceiving Vader's distraction during the duel, Fane Peturri attempted to seize the opportunity to escape the moon. However, with Celeste subdued and held by clone troopers, Vader intercepted him, correctly identifying Peturri as an agent of Palpatine himself, dispatched to monitor Vader. Vader revealed that while Force-sensitivity offered protection from the rakghoul plague to both himself and Celeste, a mere environmental suit was insufficient to shield Peturri from Sith magic. Consequently, Peturri transformed into a rakghoul, and Vader promptly eliminated it.
With Vader preoccupied by the rakghoul Peturri, Celeste threw away the clones guarding her and retrieved her lightsaber, re-engaging Darth Vader. Amid the chaos, Schurk-Heren managed to subdue a clone trooper and seize a blaster, which he employed to liberate the remaining members of the Uhumele's crew. They immediately fled towards their vessel, intending to escape.
Recognizing the inevitability of her defeat, Celeste opted to harness the full potential of the Muur Talisman to prevent Vader from claiming it, instantly transforming all clone troopers present into rakghouls – and, regrettably, Crys Taanzer. Schurk-Heren was compelled to shoot the newly infected Crys, at which point the remaining crew of the Uhumele successfully escaped.
Faced with a sudden surge in enemy numbers, Darth Vader was compelled to abandon the conflict and retreat to his shuttle, recognizing that Celeste was unsuitable as his apprentice and that the Talisman would not fulfill his objectives. Celeste, lacking any means of departing the world, resigned herself to waiting with her rakghoul servants until another party arrived, finding solace in the knowledge that Karness Muur remained equally trapped.