While Giants Mark Time

Following their landing within the Tatooine desert's expanse, a disagreement arises between Artoo and Threepio regarding their destination, leading them to independently embark in opposing directions. Concurrently, a contingent of Imperial soldiers investigates the remnants of their escape pod, uncovering indications of droid presence. Their deduction leads them to believe that a droid is in possession of the pilfered Death Star plans.

Threepio is discovered by a clan of Jawas and brought aboard their sandcrawler; however, what he perceives as a rescue quickly turns into capture. He finds himself confined within, surrounded by a diverse assortment of droids in varying states of disrepair. Threepio's inquiry to the Jawas about Artoo-Detoo inadvertently reveals his comrade's location. Meanwhile, at the Lars moisture farm, Luke Skywalker engages in a conversation with his Uncle Owen about acquiring new droids to aid in their farm duties. Despite his lack of success in Anchorhead, Luke expresses his desire to inspect the droids carried by the next Jawa sandcrawler passing through. Despite Owen's preference against droid purchases, he reluctantly concedes.

Threepio soon discovers that Artoo has also been captured, a consequence of the information he unwittingly provided. Sometime later, the Jawas halt at the Lars homestead. While the droids are presented for sale, Artoo sabotages an R5 astrodroid. Owen proceeds to purchase the malfunctioning R5 unit, along with C-3PO, whom he deems capable of assisting his wife Beru with her tasks. The R5 unit malfunctions almost immediately, leading Owen to decide to purchase Artoo instead. Within the tech dome, Luke cleans the droids. R2-D2 plays a fragment of Princess Leia's recorded holographic message, informing Luke that the Jawas' restraining bolt is impeding the playback of the complete message. Luke removes the bolt, but nothing happens. He then departs for supper, at which point Artoo reveals to Threepio that playing the recording was a ploy to facilitate his escape and continue his pursuit of Obi-Wan Kenobi. Artoo once again ventures into the desert.

Inside the house, Owen swiftly dismisses Luke's inquiries regarding "Obi-Wan Kenobi." Furthermore, he firmly rejects Luke's request to reapply to the Imperial Space Academy, citing the increased droid labor on the farm. Upon Luke's departure, Beru cautions Owen against indefinitely postponing Luke's departure from the farm—or informing him about his father. In the tech dome, Luke discovers Artoo's escape and is terrified of what Owen will do if he finds out; but he cannot go looking for him with night falling.

Similar to the majority of subsequent radio episodes, "When Giants Mark Time" aligns with the film's events while incorporating a few supplementary short scenes. C-3PO's dialogue with the Jawas substitutes a silent scene in the film where Artoo is ambushed while moving through the desert, compensating for radio's inherent lack of visual information. Luke and Owen engage in a brief exchange during which Luke persuades his uncle to acquire droids from the approaching Jawa sandcrawler. Artoo's escape from the Lars tech dome is portrayed in another brief scene, which occurred off-camera in the film.

Artoo's sabotage of the red R5 droid is also introduced in the radio version for the first time. This action clarifies that the unit's blown motivator is part of Artoo's mission, rather than a random occurrence. In the 2017 Canon story "The Red One," narrated from R5's perspective, Artoo initiates the sabotage but is interrupted; he then explains to R5 that the fate of the Rebellion and the Galaxy depend on his mission. This convinces R5 to simulate a blown motivator of his own accord. In the same scene in this episode, Luke also calls the droid an "R5 unit" rather than an "R2 unit" as in the film. Later works in both Star Wars Legends and Canon have followed this usage.