Following the Duel on the Wheel, the Sith Naare stole the B1-series battle droid Roger's head and traveled on the Eclipse Fighter to the uncharted world where Rowan Freemaker and Roger had hidden the seventh Kyber Saber crystal. After arriving, Naare used the seventh crystal to reforge the Kyber Saber. Testing the ancient lightsaber's powers, Naare used the Kyber Saber to carve up a row of mountains and to destroy a nearby planetoid.
Shortly later, Naare was contacted by Emperor Palpatine who chastised her for playing with his weapon and derided her as a second-rate Sith. Tired of being bossed around and derided by Palpatine, Naare responded that she was wielding the most powerful weapon in the world and demanded to know why she should give it to him. When Palpatine fumbled for an answer, Naare announced that she was coming to the galactic capital of Coruscant to kill him and crown herself Galactic Empress.
Back at the Freemaker Garage on the Wheel, Rowan used his Force powers to rebuild the StarScavenger and Zander Freemaker's Blazemaker Mark II. Rowan then briefed Zander and Kordi Freemaker about his plan to trick Naare into handing him the Kyber Saber by disguising himself as the Emperor. Rowan had obtained a dark robe and a voice modulator from their earlier mission on Naboo. The Freemakers decided to travel to Coruscant, which was hosting Empire Day.
The Freemakers took the StarScavenger to Coruscant and found that half of the galaxy had gathered for Empire Day. Since the Imperial Palace was heavily guarded by Imperial Star Destroyers, AT-AT walkers, and stormtroopers, the Freemakers decided to sneak into the palace through the sewers. While navigating through the sewers, the Freemakers were accosted by a probe droid. Zander wrestled with the droid and Rowan knocked it out with his lightsaber, causing it fall into a drain.
The Freemakers then found their path obstructed by a deep barrier. Rowan used a grappling hook to erect an improvised flying fox for him and his siblings to cross. Zander falls when a DLC-13 mining droid accidentally cuts the rope. However, Rowan uses the Force to life Zander onto a mining droid, saving his older brother's life. Rowan then used his lightsaber to cut a hole into a passage leading into the palace. The Freemakers encountered two stormtroopers but Kordi immobilized them with a chain. Rowan then donned his Emperor disguise and parted company with his siblings. He then headed to the Emperor's throne room.
Meanwhile, Naare arrived above Coruscant in her Eclipse Fighter. The Emperor dispatched two Gozanti-class cruisers and their TIE fighters to intercept her. However, Naare used the Kyber Saber to destroy the ships. She then destroyed two Imperial Star Destroyers and issued a hologram warning to the Emperor that she was coming to finish him off. Unwilling to repeat Grand Moff Wilhuff Tarkin's mistake during the Battle of Yavin, Palpatine ordered an evacuation of the Imperial Palace.
He ran into Rowan but assumed that the boy was an impostor that his subordinates had prepared. Rowan then bidded his time in the Emperor's throne room. Meanwhile, Naare landed in the Imperial Palace's courtyard and tossed out Roger's head, no longer needing the droid's services. Roger was rescued by Zander and Kordi, who were pleased to see the droid. Roger then warned them about Naare's plan to kill the Emperor.
In the throne room, a disguised Rowan greeted Naare and requested the Kyber Saber. Naare then proceeded to attack Rowan with the ancient lightsaber. Rowan managed to dodge Naare's attacks and the Saber instead destroyed the throne room's furniture. Upon recognizing Rowan, Naare vowed to finish off the young boy. However, Emperor Palpatine attacked the Imperial Palace with two AT-ATs. Naare used the Kyber Saber to toss the massive walkers aside before destroying several more TIE fighters.
Despite Naare's advantage, Rowan managed to use his Force powers to call to the Kyber Saber crystals. He then wielded the weapon against Naare's Sith lightsaber and created several walls. Naare sliced through each of these walls. Rowan then used the Kyber Saber to summon up rubble to encircle Naare. Triumphant, Rowan toyed with killing her and was egged on by Emperor Palpatine, who had arrived in a Lambda-class shuttle. Upon realizing that Palpatine was trying to entice him to the dark side of the Force, Rowan rejected the Emperor's overtures and escaped with the Kyber Saber aboard the StarScavenger.
The Freemakers then fled on the StarScavenger through the skylanes of Coruscant with several TIE fighters in hot pursuit. To confuse the Imperials, Zander led them on a chase and wielded Rowan's lightsaber in order to mislead the Imperials into thinking that he had the Kyber Saber. This ploy worked and allowed Rowan and Kordi to escape with the real Kyber Saber aboard the StarScavenger. Rowan then used his Force powers and the Kyber Saber to transform the StarScavengers design. This enabled the ship to flee Coruscant undetected. Zander then fled into hyperspace as well.
Rowan Freemaker inflamed the Emperor greatly
Back at the Imperial Palace's upturned throne room, an enraged Emperor Palpatine ordered his subordinates to place Rowan Freemaker on his most wanted list. However since Luke Skywalker, Princess Leia Organa, Han Solo, Lando Calrissian, Chewbacca, and R2-D2 were already on the list, the Emperor had to settle with placing Rowan lower on the list. Naare attempted to flee but was instead cornered by Graballa and his henchmen Dengar, Baash, Raam, and others who had come to settle scores with her for breaking their agreement at the Wheel earlier. As punishment, Graballa had her frozen in carbonite.
Following the skirmish on Coruscant, the Freemakers traveled to Sullust. Heeding the story of Jedi Master Baird Kantoo, Rowan decided to destroy the Kyber Saber since he realized that it was too powerful and dangerous. Unable to return to the Wheel, the Freemakers decided to travel through the stars. However, they soon encountered the Alliance Fleet. Admiral Ackbar managed to entice the Freemakers to join the Rebel Alliance with a job offer.
The Skirmish on Coruscant serves as the main plot of the LEGO Star Wars: The Freemaker Adventures first season "Return of the Kyber Saber," the season finale which premiered on Disney XD on August 29, 2016.