Mission to Mos Eisley (episode)

Aboard a spacecraft, C-3PO, displaying impatience, implores the droid pilot to increase speed while traveling through hyperspace. The pilot, now annoyed, threatens to decelerate, leading C-3PO to move to the rear of the ship. There, he comes across a Twi'lek who collects cards featuring Rebel heroes. Recognizing Hera Syndulla on one of the cards, C-3PO begins to recount his experience of encountering Hera and the crew of her ship, the Ghost, together with R2-D2.

In the period of fifteen years following the Empire's rise, 3PO and R2 operated covertly as translators for Imperial minister Maketh Tua, working with Amda Wabo, an Aqualish arms dealer. Hera's crew, including Garazeb Orrelios, Sabine Wren, Ezra Bridger, Kanan Jarrus and C1-10P ("Chopper"), ambushes the hangar where Wabo's disrupters are being loaded. After Zeb shoots the door that Wabo is under, seemingly crushing him, R2 suggests that he and 3PO tail the "gunkbot" (Chopper) and depart for the Ghost, where Hera responds to 3PO's perceived opinion towards her crew by asking "Who are you calling ghastly?".

Once in space, 3PO and R2 are equipped with restraining bolts. Following a brief argument with Chopper, the protocol droid reassures the astromech that they hold significant value to the Empire. Zeb, overhearing this, suggests they be scrapped, but Kanan prioritizes delivering the stolen ion disruptors to their benefactor Cikatro Vizago. After they depart, 3PO takes matters into his own hands and sends a distress signal via intercom. Agent Kallus intercepts 3PO's call, tracing them to Lothal, where Hera and her crew are finalizing the transaction with Vizago. They launch an assault on the rebels using AT-DP walkers. During the conflict, C-3PO inadvertently uses the ion disruptors to obliterate the attacking Imperial forces. Subsequently, he and R2 are returned to Bail Organa—who 3PO later discovers is a prominent member of the Rebel Alliance—aboard the Tantive IV.

The space transport eventually arrives at Mos Eisley, where 3PO learns that Wuher's establishment has closed down, replaced by a cantina operated by Watto. The Mos Eisley Cantina has become a haven for droids fleeing from Jawas. He proceeds to tell the hidden droids about his and R2's pivotal role in the events leading up to and following the Battle of Yavin.

Four years prior on the Tantive IV, Leia Organa, Bail's adopted daughter, acquired the stolen plans for the Death Star. After recording two versions of "Help me, Obi-Wan Kenobi. You're my only hope," Leia conceals the plans within R2, who escapes with 3PO in a pod headed for Tatooine. Upon landing, they are captured by Jawas and brought to the Lars Homestead, where Luke Skywalker and his uncle purchase the droids after R2 sabotages the others. Following the purchase, R2 sets out to find Obi-Wan, prompting Luke and 3PO to follow. Meanwhile, on the Death Star, Darth Vader criticizes Conan Antonio Motti for over-reliance on technology, using the Force to manipulate and humiliate him.

Luke and 3PO locate the elderly Obi-Wan, who expresses surprise that Luke did not change his last name while in hiding from the Empire. R2 presents them with Leia's message, and Obi-Wan invites Luke to accompany him to Alderaan, to which Luke immediately agrees. At the cantina, the search for a pilot is cut short by an attack from stormtroopers. With Han Solo and Chewbacca joining the group, they depart in the Millennium Falcon, where Luke awkwardly practices lightsaber techniques. 3PO informs Han that the ship is being drawn into a tractor beam towards the Death Star. Concealed beneath the floor, the Imperials find the ship seemingly empty, but Vader suspects otherwise, ordering his stormtroopers to guard Leia. Obi-Wan employs his "Jedi Mind Trick" to bypass two Stormtroopers (by simply distracting them and then knocking them out with a wrench). Donning the stormtroopers' armor, Han, Chewbacca, and Luke embark on a mission to rescue the princess, while Obi-Wan proceeds to disable the tractor beam. 3PO and R2 take refuge in a closet with a rapidly firing mouse droid.

After liberating Leia, the quartet escapes into a trash compactor that nearly crushes them before R2 intervenes to deactivate it. Obi-Wan finds the task of deactivating the tractor beam surprisingly straightforward until he encounters Vader. They both apologize to each other and are about to go their own ways until they realize who the other person is. Luke and the others arrive just as Vader dispatches Obi-Wan (offscreen) before Vader sees Leia out of her cell and they escape. Luke and Han argue while manning the turrets, engaging in a firefight with TIE fighters, until Leia takes control, guiding them to Yavin 4.

Leia identifies the Death Star's vulnerability as a ventilator shaft susceptible to proton torpedoes, describing the mission as a "one in a billion chance" with a high likelihood of casualties. Luke and the others accept the daunting odds without hesitation. 3PO watches R2 depart in Luke's X-Wing, questioning the astromech's willingness to face such peril. During the battle, Luke hears Obi-Wan's voice and successfully launches the torpedoes into the ventilation shaft. Simultaneously, Han shoots Vader's TIE Advanced fighter, causing it to lose control. At the award ceremony, 3PO, distraught over R2's apparent demise, is overjoyed to see him return, but then falls. The tray he carries holding Luke and Han's medals remains intact, but Chewbacca's breaks into three pieces, explaining why Chewie never received a medal.

Concluding his narrative, one of the droids informs 3PO that R2 was spotted with a mysterious stranger, who was purchasing droids from the Jawas. Upon exiting the cantina, 3PO sees the hooded figure and R2 boarding a LAAT gunship. Unable to board the departing ship, 3PO enlists Chewbacca and the Falcon to pursue the ship into space.