The Forgotten Droid " The Forgotten Droid " is the nineteenth episode of the second season of the animated television series " Star Wars Rebels " . It is the thirty - fourth episode of the series overall . The episode premiered on March 16 , 2016 on Disney XD . Official description . " When Chopper steals a replacement for his original leg , he separates from the " Ghost " crew and finds himself stranded on an Imperial ship . The grumpy astromech meets an inventory droid in service of the Empire , but will this new acquaintance become friend or foe ? " Synopsis . Left behind . After the theft of the Imperial fighter carrier above Ryloth , the rebel fleet was still looking for a safe haven to establish a new base . Commander Jun Sato convened a meeting aboard the new flagship that was attended by the crew of the " Ghost " and the former Clone Captain Rex . By cross - referencing several Galactic Republic and Lasat maps , the rebels had identified the planet Berzite ' s moon in the Yost system as a prospective location . Ketsu Onyo , Sabine Wren ' s friend , recommended Berzite ' s moon on the grounds that the Empire lacked a presence there . However , the trip was delayed as the rebellion ' s fighter carrier did not have enough fuel to make the journey . Sabine , who had been tracking Imperial fleet movements , suggested stealing an incoming shipment of fuel from the Imperial depot at Horizon Base . Sato approved Sabine ' s plan and the crew of the " Ghost " departed for Horizon Base to obtain the fuel . Upon landing , the rebels made their way to the Imperial fuel depot while the astromech droid Chopper was assigned to watch out for Imperial forces . Kanan Jarrus ' plan was to blast their way out after they have obtained the necessary fuel supplies . However , Chopper was distracted by the sight of a new droid leg being sold at a nearby stall . Chopper had an improvised left leg which did not fit him well . When Chopper raised the matter to Hera Syndulla , Hera reminded him that they were not on Horizon Base to shop and that they were on an urgent mission . Despite Chopper ' s protests , Hera ordered him to keep a watch for Imperial forces and to alert them . Before leaving , Garazeb Orrelios and Ezra Bridger teased Chopper about " getting a leg up " and going " shopping . " Defying Hera ' s orders , Chopper activated his rocket booster and flew to the stall selling the droid leg . The stall was run by an Ugnaught scrap merchant . Noticing Chopper , the Ugnaught merchant assured the droid of the quality of his produce but admitted to his involvement in shady dealings . The merchant offered to sell the leg to Chopper for 500 credit s . When Chopper revealed that he lacked the funds to obtain it , the Ugnaught merchant ordered him to leave . Meanwhile , the other five rebels approached the fuel depot and found that it is heavily guarded . While Hera reiterated that the rebels could not leave without getting the fuel , Kanan told them to get the fuel " quietly with no complications . " Still determined to get the spare leg , Chopper stole it for himself and tried to flee back to the " Ghost " but was spotted by the Ugnaught merchant , who alerted several stormtrooper s . Meanwhile , the other rebels fled back to the " Ghost " without Chopper . Left behind on Horizon Base , Chopper managed to dodge his Imperial pursuers by running aboard a departing Class four container transport . He hid in one of the hatches . Meanwhile , aboard the Imperial cargo ship , the Imperial RA - 7 protocol droid AP - 5 told the captain on the ship that he is off by . 002 . The captain harshly responded by belittling AP - 5 for being a " useless droid " before ordering him to go check on the ship ' s manifest . Two unlikely friends . AP - 5 walked past some stormtroopers who ignored him . He noticed that a hatch was open and investigated it for any stowaways . Chopper tried to elude AP - 5 but was eventually caught by him . AP - 5 recognized Chopper as a stowaway and the rebel droid who had stolen a droid leg from Horizon Base . When AP - 5 noticed that Chopper had a spark projector , Chopper revealed that he was a war hero . In return , AP - 5 told Chopper that he was a veteran of the Clone Wars who had served as an analyst droid for the Galactic Republic during the Ryloth campaign . Chopper also told AP - 5 that he flew a BTL - A4 Y - wing assault starfighter / bomber which crash - landed on Ryloth but was rescued by Hera . Finding a friend , AP - 5 told Chopper about his unhappiness at being reassigned to inventory duty and being constantly belittled by his Imperial superiors . AP - 5 expressed his admiration for Chopper ' s fortitude . At that point , the Imperial captain interrupted their conversation via comlink and asked AP - 5 about the manifest and warning him about the stowaway droid . Chopper then used his electro - shock prod to disable AP - 5 ' s restraining bolt , freeing the droid . Shortly later , the Imperial captain arrived and proceeded to chastise AP - 5 for neglecting the ship ' s manifest while asking him about the intruder . When the captain noticed AP - 5 ' s missing restraining bolt and attempted to apply a new one , Chopper appeared and attacked the Imperial officer . The officer grabbed Chopper during the struggle and called for reinforcements through his comlink . However , Chopper managed to stun him with his electro - shock prod . With nothing left to lose , the two droids decided to join forces and Chopper devised a plan to seize control of the ship . While AP - 5 thought Chopper ' s plan had a 10 . 5 % chance of succeeding , he still agreed to help . Chopper lured the stormtroopers into the cargo compartment and then jettisoned it into space . The two droids then argued over who should lead the ship . Meanwhile , in hyperspace , the other crew of the " Ghost " headed back to the rebel fleet . On the way , Ezra , despite his acrimonious relationship with Chopper , urged his fellow crew to go back for the droid . However , Hera criticized Chopper for only looking out for himself and allowing himself to get distracted by the droid leg . She also stressed that the rebel fleet was more important . Shortly later , they received a transmission from Commander Sato that the rebel fleet was under attack from Imperial forces . When they exited hyperspace , they saw the Imperial fleet attacking the rebels . Back on the cargo ship , AP - 5 decided to go for his programmed destination . Finding a new base . Aboard another Imperial warship , an Imperial officer informed Admiral Kassius Konstantine that the " Ghost " had entered the system . Realizing that the " Ghost " was carrying stolen fuel supplies for the rest of the fleet , Konstantine immediately ordered all remaining fighters to focus fire on the " Ghost " . The Ghost ' s crew was assisted by Ketsu who helped them take out the attacking TIE fighters , managing to enter the cruiser . On the Imperial cargo freighter , AP - 5 allowed Chopper to serve as the ship ' s helmsman . Chopper changed the coordinates , much to AP - 5 ' s concern . He also told AP - 5 that he should come with the rebels , as they were kinder than his Imperial superiors . Back at the rebel fighter carrier , Hera managed to land the " Ghost " with much difficulty . Zeb and Ezra began unloading the fuel supplies while Hera received contact from Chopper through the ship ' s intercom . Hera was initially annoyed with Chopper for abandoning his post and informed him that the rebel fleet was preparing to depart for the Yost system . Over - hearing the conversation , AP - 5 looked up the Yost system and informed them that an Imperial fleet was lying in ambush there . Chopper relayed this information back to Hera . When Hera expresses skepticism , Chopper assured her that AP - 5 was telling the truth . AP - 5 cross - searched both Chopper and the Imperial data to look for any potential havens and finds one : the planet Atollon . Meanwhile , Hera informed Commander Sato that the Yost system was unsafe and that they have received coordinates to a new system . The cargo ship captain , regaining consciousness , headed back to the bridge to confront the hijackers . Taken by surprise , AP - 5 claimed that Chopper was holding him hostage . The captain however saw through the ruse and attacked the two droids . While AP - 5 manned the controls and expressed gratitude for Chopper ' s friendship , Chopper fought the captain and managed to knock his blaster pistol out of his hand . The two fought with the captain gaining the upper hand due to his bigger size . AP - 5 was about to transmit the new coordinates to Hera when he was shot twice by the captain . An enraged Chopper fought back even harder and managed to stun the captain again . Chopper then transmitted AP - 5 ' s coordinates to Hera and the rebel fleet . Despite their victory , AP - 5 was badly damaged by the blaster bolts and began to shut down . Before powering down , he managed to tell Chopper that he was glad to have made a new friend , to Chopper ' s dismay . Using AP - 5 ' s information , the Phoenix rebel fleet headed towards the new coordinates . Later , Hera and Kanan check out the coordinates and finds that Atollon was indeed safe and void of any Imperial presence . Meanwhile , Sabine fixes AP - 5 ' s thermosensor s by salvaging parts from the spare leg had Chopper stolen . AP - 5 met the crew of the Ghost for the first time . After learning that Chopper had sacrificed his new droid leg to repair him , AP - 5 remarked that Chopper had a malfunctioning logic circuit . When Chopper uttered a rebuttal , AP - 5 responded that the former ' s remarks were so foul that they could get him disintegrated in six systems . As the two droids departed the common room , the rest of the crew watched with bemusement .