The Second duel on unidentified desert moon was a lightsaber duel fought nine months following the Battle of Yavin between Luke Skywalker and unstable Human female Jedi Knight Celeste Morne on a desolate moon orbiting a gas planet.
In 19 BBY the Sith Lord Darth Vader came in possession of Dreypa's Oubliette, an ancient Sith artifact which placed it's occupant in stasis. He believed that the oubliette contained a powerful Sith artifact known as the Muur Talisman and a Jedi from centuries ago. In the hopes that he could claim the power of the Talisman and gain the mystery Jedi as an apprentice, Vader opened the oubliette where a healthy female Jedi, Celeste Morne, emerged. Once she realized that Vader was a Sith Lord a lightsaber duel began between the two of them.Even though Vader disarmed her, Celeste used the Muur Talisman to transform Vader's stormtroopers into rakghouls, forcing him into retreat off the moon and at the same time leaving her stranded.
About nineteen years later Vader's thoughts drifted back to Celeste and he wondered if he could use her against the current Rebellion against the Sith-led Empire. He sent an Imperial convoy on a mission to confirm whether Celeste was still alive. As the convoy descended to the moon's surface transmissions ended when Celeste transformed the pilots into rakghouls and crashed the shuttles. Thus Vader knew Celeste still lived and he ordered former Rebel spy, Wyl Tarson to send a message to the Rebellion concerning a secret Imperial weapon. In response a group of rebels lead by Luke Skywalker and Princess Leia Organa landed on the moon in order to follow up on the message.
For almost twenty years Celeste had lived alone on the moon and the spirit of the Sith Lord Karness Muur haunted her to the point of insanity, developing not only a hatred for Vader, but also for the Jedi.Therefore, as the rebels began to survey the crash site of the Imperial shuttles, the rakghouls Celeste controlled attacked them and dragged Luke and Leia to a cave where Celeste waited ready to strike.
Morne attacks Luke Skywalker.
The battle began with Celeste Morne assaulting Luke Skywalker. Luke deflected the first few strikes, but then Celeste used telekinesis to overpower Luke Skywalker. Pushed on his back foot, Luke suffered multiple hits from Celeste Morne before being kicked aside and defeated. Morne then held her Lightsaber next to the throat of a defeated Luke.