Relics of the Old Republic " Relics of the Old Republic " is the fourth episode of the " Star Wars Rebels " animated television series ' second season . It is the nineteenth episode of the series overall . After premiering at on October 8 , 2015 , the episode aired on October 21 , 2015 on Disney XD . Official description . " While Kanan continues to struggle with trust issues , the other rebels begin to form friendships with the old clones . And when Agent Kallus arrives , all must join together to battle the Imperials . " Plot summary . Due to Wolffe ' s actions , the Galactic Empire has tracked the Spectres to the planet Seelos . Admiral Kassius Konstantine and the Imperial Security Bureau Agent Kallus come to the Seelos system to capture or eliminate the rebels once and for all . At the clones ' old All Terrain Tactical Enforcer , Sabine Wren is working on fixing the damage to the " Phantom " when Kanan Jarrus contacts her to ask how its going . He then contacts Hera Syndulla , in orbit on the " Ghost " fixing the ship ' s hyperdrive . She tells him there ' s no sign of the Empire , just before the Imperial Star Destroyer " Relentless " drops out of hyperspace , prompting Hera to exasperatedly comment about her tempting of fate . Hurriedly , she shuts down all of the starship ' s systems , including her astromech droid Chopper , who protests , to avoid being detected by the Empire . Before parting company , Rex gives Ezra Bridger a datachip containing a list of former Republic bases in the Outer Rim Territories and Mandalore . Ezra tells Rex that the clones should join the rebellion but Rex politely declines , saying that he has seen too many battles . However he , Gregor and Wolffe offer to stay behind in order to delay the Empire so that the Spectres can escape aboard the " Phantom " and rejoin the " Ghost " in space . Contacting the clones , Agent Kallus demands that they hand over the rebels . Wolffe denies that there are any Jedi or rebels around , claiming that his old cybernetic eye must have been malfunctioning . Kallus reveals that he has images from the probe droid revealing the presence of rebels , at which point Rex enters the conversation and tells the ISB agent that if he wants a fight , he should have brought a better class of soldier than Imperial stormtrooper s . Kallus smugly responds that they are loyal and he has a great many of them , and Rex retorts that he ' s going to need " all " of them before ending the transmission . A sandstorm stirs up near the modified AT - TE that prevents the rebels from departing . Agent Kallus deploys three AT - AT walkers to destroy the clones and rebels . Rex has the idea of fleeing " into " the sandstorm , with Kanan and Ezra Bridger using their Force powers to guide the walker . The Imperials will be blinded , but the rebels won ' t . Kanan , despite his mistrust of the clones , agrees to go along with the plan . He guides the AT - TE into a position where they are surrounded by Kallus ' three AT - ATs , telling Rex that this is their best opportunity to destroy one of them . Ezra and Sabine are sent up to the AT - TE ' s main gun in order to make the shot , with Rex loaning the Padawan his helmet as protection from the storm . With guidance from Kanan , Ezra makes the shot , hitting one of the AT - ATs in the neck and destroying it , allowing the clones ' walker to flee the remaining two . Back in space , Admiral Konstantine receives a transmission from Darth Vader , ordering him to rendezvous with his shuttle in space . Konstantine protests that this will compromise Kallus ' ground mission , but the orders are clear , and the " Relentless " departs the system . Hera , working with Chopper , who she had reactivated at low power , witnesses this . She ' s not sure what the Star Destroyer ' s departure means , but orders Chopper to continue working on repairs . After exiting the sandstorm , the Spectres prepare to depart on the " Phantom " to rejoin the " Ghost " in space . Despite Ezra ' s willingness to stay and fight , Rex commands Ezra to leave , as the clones prepare to hold off Kallus and his two remaining AT - AT walkers . As the rebels depart on the " Phantom " , Kallus ' AT - AT walker manage to subdue the clones ' walker . Before Kallus can destroy the clones , Ezra convinces Kanan and the other rebels to turn back and help the clones , pointing out that the old soldiers are willing to fight to the death . Despite his misgivings about the clones , Kanan agrees with Ezra and flies the " Phantom " back into the fray . While Sabine pilots the shuttle , Kanan , Ezra and Garazeb Orrelios commandeer one of the AT - ATs and turn its weapons on Kallus ' AT - AT walker . With his AT - TE no longer trapped under the AT - AT walker ' s legs , Rex is able to destroy Kallus ' walker with a critical hit . Kallus and his remaining men flee the battle on a speeder , while the clones salute Ezra and Kanan . Rex agrees to join the rebels , and returns with them to Phoenix Cell . Meanwhile in space , Admiral Konstantine greets the shuttle that landed in his Star Destroyer ' s hangar . Instead of Vader , however , the Admiral is surprised to see the Fifth Brother , a Force - sensitive Inquisitor . When Konstantine tells him that his diversion may have compromised Kallus ' mission , the Fifth Brother expresses indifference and claims that he will succeed where Kallus and Konstantine had failed . Returning to the Phoenix rebel fleet , the Spectres and Rex reunite with Ahsoka Tano . When Rex comments that Ahsoka has grown old , the former Jedi Padawan responds that " It had to happen sometime , Rex " as they embrace . The Spectres , Ahsoka and Rex walk off together . Continuity . In Rebels Recon # 2 . 06 : Inside " Wings of the Master " , Lucasfilm Story Group spokesperson Pablo Hidalgo confirmed that Gregor and Wollfe stayed behind on Seelos and made the remaining AT - AT walker their new home .