"Relics of the Old Republic" is the fourth episode of the second season of Star Wars Rebels. It is the nineteenth episode of the series overall. It was screened in tandem with "The Lost Commanders" on October 8, 2015 at New York Comic Con, and released on October 21, 2015 on Disney XD.
On Seelos, the Rebels and the Clones were still recovering from the probe's attack, and the Phantom still remained damaged as repairs were taking much longer than they expected. Worst of all, there was no telling when the Empire would show up and a huge sandstorm was heading their way. Rex gave the Rebels a list of coordinates to every forgotten Republic base, Separatists installation, pirate hideout, and smuggler's den in the outer rim that would be of some use in their search of a base. The Rebels were grateful and all, except Kanan, tried to convince the clones to reconsider joining their Rebellion but all they said was their war was over and did not wish to get caught up in another. Ezra remained concerned for them since the Empire was coming, but Rex assured him they would be fine and they could take care of themselves. Kanan contacted Hera, who remained in orbit and still making repairs on the Ghost. He told her of their current situation and then asked if there was any sign of Imperial ships. Still busy, Hera told him there was nothing to report. But she spoke too soon as an Imperial Star Destroyer emerged from hyperspace.
Hera warned the others about the arriving Star Destroyer, and to avoid detection, she shut down all power systems on the ship, including Chopper. Drifting in space, Hera watched four TIE Fighters launched from the Star Destroyer and head down to the planet's surface, but they didn't spot or detect Hera. Meanwhile back on the surface, the clones received an incoming transmission from Agent Kallus, requesting them to transmit their coordinates so they can investigate the Jedi sightings Wolffe reported. Wolffe and Rex try to cover up the truth but Agent Kallus could see through their lies, and demanded them to surrender the Rebels or they will be destroyed. The clones refused and ended transmission, when suddenly a TIE Fighter spotted their walker and attacked. The Rebels and the clones prepared for battle and took evasive maneuvers. The TIE Fighter came round for another pass and opened fire. The Rebels tried to return fire but couldn't get a shot with hand weapons, and the walker's cannon wouldn't make any difference in their situation. Rex handed Gregor a bazooka, and after the TIE made another pass Gregor took aim and destroyed the TIE with one shot. Then after a brief victory, the Rebels got back to work in repairing the Phantom. Back in orbit, Admiral Konstantine informed Agent Kallus that they have marked their location and asked if they should commence an orbital bombardment. Kallus said no and told him to prepare a ground assault instead.
Back on the surface, the group continued their repairs on the Phantom and triued to keep ahead of the sandstorm. Rex noticed Ezra riding the cannon and showed him the controls. Ezra asked Rex what it was like fighting in the Clone Wars, and all he could say that it was never dull. He then told him about the Jedi he fought alongside, and the number of times he trusted him with his life. Sabine informed everyone that repairs were almost done and they would soon be able to leave, while Ezra still remained unkeen about leaving Rex, Wolffe and Gregor behind. Just then they heard some distant thudding and spotted three giant Imperial Walkers heading right for them. From what Rex could tell, they were fitted with reinforced armor plating, heavy cannons and antipersonnel blasters. Then after dropping the Joopa to reduce weight, Rex ordered Wolffe to turn them about and retreat into the storm, which would give them a blinding advantage against the Imperials. Kanan was against this at first until Rex reminded him of Ezra's Jedi senses and his own, which would help them navigate through the storm. The Imperials were too against entering the storm but Kallus ordered them to continue their pursuit. Soon both the Rebels and the Imperials were inside the storm, and with sensors useless they were both navigating blind. Using The Force, Kanan and the clones attempted to outmanuever each other until Kallus was able to surround the AT-TE with an enveloping manuever. Rex sent Ezra and Sabine to man the AT-TE's main gun and destroy one of the AT-ATs using the Force, while Kanan remained with the clones to guide them out. With Kanans help, Ezra turned the cannon to a nearby walker. Even though he couldn't physically see it, he was able to sense it through the Force. He took careful aim, and with one shot he took out the walker. They also revealed their location to the two remaining walkers and made a run for it.
Meanwhile, Admiral Konstantine's ship remained in orbit and the Ghost remained a drift and powerless but still undetected. Just then one of the bridge officers informed Admiral Konstantine that they had just received new orders to rendezvous with Darth Vader's shuttle immediately. From the Ghost, Hera noticed the Imperials leaving orbit and depart into hyperspace. Back on the surface, the Rebels and the clones made it out of the storm and the Phantom's repairs were complete. Rex urged them to take off but Ezra refused to leave them behind. Despite his objections, the decision had been made and the Rebels took off, leaving the clones to hold off the Imperials. The Imperials soon emerge from the storm and the battle against the three walkers began. Overpowered, the clones' walker took a heavy beating but kept on going. They charged right into the legs of Kallus' walker and tried to top them over. However, the other walker opened fire on them and it was almost over for the clones, when suddenly the Rebels came back to help them. Kanan, Ezra, and Zeb highjacked the second walker and used it to help the clones destroy the leading walker, winning the battle and forcing Kallus and his men to retreat.
Meanwhile Admiral Konstantine's ship was at the rendezvous point just in time for Vader's shuttle to arrive. But instead of the Sith Lord being on board, an Inquisitor known as the Fifth Brother disembarked from the shuttle instead. When the Admiral asked about his presence, the new Inquisitor vowed to succeed where he and Kallus had failed. Following their victory, Rex decided to join the Rebellion and returned to the fleet, where He and Ahsoka had a warm reunion.
- Taylor Gray as Ezra Bridger
- Freddie Prinze, Jr. as Kanan Jarrus
- Vanessa Marshall as Hera Syndulla
- Tiya Sircar as Sabine Wren
- Steven Blum as Garazeb Orrelios / Imperial Technician #1 / Imperial Technician #2
- Dee Bradley Baker as Captain Rex / Commander Wolffe / Captain Gregor / Kassius Konstantine
- Ashley Eckstein as Ahsoka Tano
- Philip Anthony-Rodriguez as The Fifth Brother
- David Oyelowo as Alexsandr Kallus
- Dave Filoni as AT-AT Pilot
- This episode is the second installment of a multi-part storyline, continuing where "The Lost Commanders" left off.
- The second Inquisitor, known as the Fifth Brother, makes his debut appearance in this episode.
- His design was inspired by unused artwork generated for The Force Awakens.
- The Imperial AT-ATs and their pilots make their series debut in this episode.
- The design of the AT-AT is a hybrid of designs seen in early illustrations by Ralph McQuarrie and Joe Johnston for The Empire Strikes Back.
- The scene where Hera shuts down all powers systems on the Ghost, including Chopper, is a possible callback to the Star Wars: The Clone Wars episode "Rising Malevolence", where Anakin, Ahsoka and Plo Koon must shut down all power systems, including R2-D2, to avoid detection.