The fight on a barren moon was a lightsaber duel fought between Jedi Master Obi-Wan Kenobi and Dark Lord of the Sith Darth Vader on a barren moon, taking place in the moon's dry lands and a labyrinth of rock pinnacles during the Great Jedi Purge.
The Jedi Master had lured the Sith Lord to the moon in a bid to give the Hidden Path time to escape. Kenobi confronted Vader not far from the Dark Lord's landing site. His former apprentice asked if he was ready to finish their battle to which Kenobi ignited his lightsaber and reaffirmed his resolve, assuming a classic defensive stance. The Sith Lord replied with murderous intent before igniting his own saber and striking the first blow.
Both Jedi and Sith initially fought evenly against each other with Vader's strikes, slashes, lunges, and ripostes met by Kenobi's blocks, parries, dodges, and counterstrikes. Kenobi soon sought to end the duel by landing two strong, sudden blows on Vader's blade to knock the Dark Lord off-balance and telekinetically dislodge a nearby pillar on top of him but Vader caught it with his own powers. The Sith Lord acknowledged that his former master had lost none of his abilities but quickly boasted he was still no match for him. Vader swiftly proceeded to gain the upper hand, pummeling Kenobi with lightsaber strikes, force-guided boulders, and his own armored fist before using his power to collapse the ground beneath him and bury him alive by collapsing the stone columns around them. Declaring his victory, the Sith Lord turned and left for his shuttle. Kenobi had survived but was slowly being crushed by the combined weight of the rubble and his own guilt. However, thoughts of his young charges allowed him to put those feelings aside and gave him the strength he needed to blast himself free and set off to re-engage the Dark Lord. He caught the Sith Lord before he reached his shuttle, attempting to cut him down from behind, only to meet Vader's blade instead. Abandoning his customary defense, Kenobi launched a furious lightsaber assault that drove the Dark Lord back. Vader attempted to catch Kenobi's blade with telekinesis but the Jedi Master quickly broke his hold and retaliated by pushing him into a distant pillar. Taking advantage of the momentarily dazed Sith Lord, Kenobi used his powers to lift the rocky debris around them and hurl it at Vader in a massive telekinetic onslaught. A frustrated Vader attempted to retake the offensive but Kenobi soon recovered and renewed his attack. The two former brothers-in-arms traded saber blows and grapples before Kenobi used his lightsaber pommel to smash Vader's chest control panel unit, heavily damaging his armor's life support system. The Sith Lord managed to block a killing strike from the Jedi Master but Kenobi hit him from behind with a piece of force-propelled debris. Desperate, Vader made a overhead strike that Kenobi dodged and immediately countered with a slash that caught the Dark Lord in the back, driving him to his knees. Forcing himself back to his feet, Vader once again struck at Kenobi only to blocked and telekineticaly pushed back against a debris pile. Kenobi then launched himself at the Sith Lord in a running leaping slash, avoiding Vader's counterstrike and slicing open his helmet.
At first, Kenobi moved back and assumed a ready stance but stood down as Vader visibly struggled. The sight of the Sith Lord's scarred face stunned Kenobi into calling him by his old name; he apologized to his former apprentice for his past failings. Vader responded by proclaiming he had fully embraced his new identity and reaffirmed his hatred of Kenobi. Upon hearing this, the Jedi Master finally let go of his guilt and departed with the belief that his friend was truly gone, ignoring the Dark Lord's impotent screams of rage. He would later describe Vader as "twisted" and "more machine than man" to his new Padawan: Anakin Skywalker's son, Luke.
The fight on a barren moon first appeared in the sixth episode of the Obi-Wan Kenobi television series, which aired on June 22, 2022. The scenes on the moon were filmed in the virtual LED set known as the Volume. Ewan McGregor, the actor who played Kenobi, was suspended with wires when his character sliced off his mask. Vader was attached to wires for when he was Force pushed by Kenobi.
According to Stuart Beattie, writer for Obi-Wan Kenobi, the idea that Kenobi could confront Vader was based on the film Star Wars: Episode VI Return of the Jedi. There is dialogue where Luke Skywalker tells Vader "I know there is good in you," who responds "Obi-Wan once thought as you do." Obi-Wan Kenobi retroactively had this dialogue reference the fight on a barren moon, where Kenobi thinks there is still good in him.