This takes place simultaneously with "Hux's Personal Mission"*
In the blue tunnel, Jack is seen reading the journal of Obi-Wan Kenobi about the true meaning of his former apprentice turning to the dark side, helping out a young Luke Skywalker, and the drought on Tatooine.
"Hmm-hmm! Good old Obi-Wan Kenobi had to stick up for the townspeople on Mos Eisley while fighting off Jabba the Hutt's criminal gang for water taxes from the look of it."
S1-M33 beeps about the Jedi Master from the past.
"He sure was an inspiration, Simee!" Jack commented. "As far as I'm concerned, Palpatine manipulated Anakin's mind before trapping him in a black suit of armor."
The alarm goes off, signaling they have reached their destination.
"Well, here we are!" Jack said.
The fighter exits hyperspace, revealing a reddish-orange planet known as Mustafar, where Jack and his team fought the First Order there before Jacen got into a coma.
S1-M33 beeps in a terrifying tone.
Jack tells him to calm down. "This is the place where everything is all fiery! Simee! Welcome to Mustafar!"
After entering the atmosphere, S1-M33 beeps about the planet's harshest conditions.
"Well, this concerns me too, Simee!" Jack replied. "This where Jedi come to die! However, this is where Darth Vader was burnt to a crisp after being defeated by Obi-Wan Kenobi, who was his master."
S1-M33 chirps sadly about this.
"I know how sad it would have been for Anakin struggling to save Padme from death." Jack sadly replied.
But the Jedi notices the fortress of Darth Vader is seen crumbling in ruins, where there are trees growing. As soon as the X-Wing enters the abandoned hangar in order to fuel up for their next adventure.
S1-M33 beeps about the vacant castle. Knowing there is some time to look around.
Jack laughs briefly at this moment.
"Of course, Simee! Now let's have a look around, shall we?"
The two stroll around the still lit hallways traveling from room to room, where Vader's throne room once stood at this very location.
"Anakin was a monster at the time when started communicating with the Inquisitors and his master for some reason." Jack explained while observing the chair.
They head for another room, where the bacta tank was located. But S1-M33 glanced at its empty case.
The droid beeps in concern about Vader's burns.
"That bacta sure hasn't healed his injuries for a long time due to lava burning his appearance." Jack revealed.
The next room they arrived in was the collection of Vader's trophies. Momentarily, Jack notices something on the pedestal.
"What is that?" Upon noticing the lightsaber hilt identical to Luke Skywalker's, turning out to be the hilt of Obi-Wan Kenobi.
"This resembles Master Skywalker's lightsaber, but it's different in a certain way." Jack recognizing the hilt.
A few seconds later, he activates to blade, revealing a blue light, which Jack was in complete awe of this moment.
"Whoa!"
S1-M33 chirps in awe upon looking at the blue blade until the Jedi turns it off and puts it in his bag.
"Well, we found what was in Vader's trophy room!" Jack said in relief before heading back to the hallways and to his X-Wing.
Meanwhile, with Leia and her crew on Anoat.
"General! We have intel about the castle on Mandalore." Connix arrived about some information on Mandalore. "Rey and her crew are not responding."
Leia sighs in worry, not to mention her nephew, Jacen.
"This is why this mission is not well for granted. At least we're on the very top of that."
C-3PO looks at the general of the Resistance in concern about the mission.
"Oh, dear! Has this mission gone totally insane like what happened a long time ago?"
"Not exactly, Threepio!" Leia answered while concerning the mission. "It was only three decades ago!"
"Well in my point of view, Artoo and I had been through many adventures right before you and Master Luke were born." The protocol droid explained.
Leia was in awe of this moment.
"Unbelievable! You two have been through long ago?"
"Exactly, General Leia!" C-3PO answered with determination.
A Resistance officers came into view and talks to Leia.
"General! We've finally set up camp!"
"Good job!" Leia acknowledged.
Back on Mustafar, Jack and S1-M33 made it to their fighter, which has been fueled.
"I'm beginning to see some trees growing out of the ground." He noticed that the planet has been covered in lava for centuries. "Mustafar was once a lush green world filled with animals and plants until Lady Corvax misused the mysterious artifact known as the Bright Star in the Aeon Engine, which has turned this world into an angry fiery world."
S1-M33 beeps about the planet's condition.
"Until then, the descendant of Lord Corvax arrived and destroyed the Bright Star before Vader could overuse it to revive Padme." Jack explained more of this. "With the artifact destroyed, Mustafar's ecosystem is slowly returning to its original state."
S1-M33 chirps in response to this story.
"Yes, of course you may be right, Simee!" Jack chuckles for a moment. "At least the trees are returning. But there's no water around here!"
Thus, concerning the lack water on an angry planet, Jack and S1-M33 board the X-Wing before taking to find out more clues.
Upon arriving at the abandoned Klegger Corp Mining Facility, Jack landed the fighter before S1-M33 gets through it until the Jedi climbs out before closing the cockpit.
While stepping in the old Separatist base, the duo began to look around for some clues. However, Jack looked at the now decomposed body of Viceroy Nute Gunray, now a skeleton.
"Damn, what a poor guy!"
S1-M33 was on the other side of the area.
He beeps at the sight of a dead Wat Tambor, who was also a skeleton.
Jack comes up to the droid and tells him "Well, it looks like Vader made his onslaught on those Separatists under the behest of Palpatine as of lately.".
The astromech droid beeps with concern about Anakin's dark side.
"Years later, his son, Luke redeemed him by defeating the emperor before dying." Jack explained.
Minutes later, the two came out of the abandoned base before getting on board the fighter. When the ship takes off before leaving the atmosphere until entering hyperspace.
"Next stop: Coruscant!" Jack said while piloting the ship.
S1-M33 whistles about their next destination.
We found out what Jack and S1-M33 were doing during "Hux's Personal Mission", following their adventure from Geonosis before heading to Mustafar, which ecosystem is coming back from hiding. Did I mention the events of "Vader Immortal"? The events of "Revenge of the Sith" were also referred.
