As the opening scroll mentions at the beginning of the story, the Rebel Alliance, fighting the 19-year-old Galactic Civil War, emerges from a secret Rebel base and finally wins their first victory against the tyrannical Galactic Empire, led by Emperor Palpatine. Princess Leia Organa's ship, the Tantive IV, carrying secret plans to the Empire's superweapon, the Death Star, is pursued by an Imperial Star Destroyer. During the fighting, two droids, the fussy C-3PO and the feisty R2-D2, escape into one of the Tantive's secret corridors. The Tantive is disabled and swallowed up into the enormous Star Destroyer via a magnetic field. Imperial Stormtroopers blast their way into the Rebel ship; when the ship is brought under Imperial control, Darth Vader arrives to assess the damage. Princess Leia records a holographic message and stores it into the memory banks of R2-D2, then disappears as C-3PO arrives to discover his counterpart. The stormtroopers capture many Rebels, while Darth Vader questions the Tantive's commander, Captain Antilles (C3P0's former master), about the secret plans. Grabbing Antilles by the throat, Vader demands an answer, but when he is unable to obtain any, the Dark Lord lifts him off of his feet and chokes the captain to death. While conducting a thorough search ordered by Vader, stormtroopers discover Princess Leia and capture her. The droids, meanwhile, use an escape pod (which R2-D2 programmed) and begin their journey to the planet Tatooine, a planet in the largely-ignored frontier region. Leia is later brought to Lord Vader for questioning, but when Leia flatly denies being part of the Rebel Alliance, he orders her to be held prisoner, knowing she is now his only hope in finding the secret Rebel Base. On Tatooine, the droids (after being captured by scavenger creatures called Jawas) come into the possession of Owen Lars and his young nephew, Luke Skywalker, a young, frustrated resident of one of Tatooine's remote settlements. That night, while cleaning the droids, Luke triggers part of a holographic message from a mysterious, attractive woman (Princess Leia). Later, at dinner, Luke suspects that the droids might have been stolen, and that R2 really belongs to an "Obi-Wan Kenobi". Uncle Owen denies it and tells Luke to have the droids' memories erased by morning. In addition, Owen refuses to honor his agreement to allow Luke to apply to the Academy that year and Luke is left frustrated with a bleak future on the farm. Returning to his garage before nightfall, Luke discovers that R2-D2 has escaped. C-3PO suggests Luke go after him, but nighttime is dangerous due to the increasing amount of Sandpeople, so they decide to wait until morning.
Early the next day, Luke and C-3PO enter the Jundland Wastes and find R2D2, but suddenly Sandpeople appear. While checking out the situation, Luke and C-3PO are attacked by one of the Sandpeople. As the Tuskens ransack Luke's speeder after subduing the farmboy, the sound of a Krayt dragon is heard, scaring off the Tuskens. It is revealed that the sound was made by none other than Obi-Wan Kenobi, now going by the name of "Ben." Ben discovers the unconscious Luke and a partially damaged C-3PO. Luke wakes up and sees Ben, who reveals his true identity and with the pending return of the Tusken raiders in force to consider, Ben takes Luke and the droids back to his hut. While Luke repairs C-3PO, Ben tells of his days as a Jedi Knight and the Old Republic and reveals to Luke that his father was one as well. As a token of good faith, the old Jedi hands Luke his father's lightsaber which Luke is able to activate without any difficulty. Ben explains about how the Jedi kept peace in the galaxy before the Dark Times. Luke then asks how his father died. Ben tells Luke he was betrayed and murdered by Darth Vader, a former pupil of Ben's before he turned evil, then talks about the mysterious energy field called the Force. Finally, Ben and Luke see the entire holographic message from Princess Leia, who asks for Ben's assistance to take the droid and the plans to the planet Alderaan if the Rebellion is to survive. Ben invites Luke to come with him to Alderaan, but the young Jedi-to-be is reluctant at first citing his responsibilities back home, eventually offering to transport Ben and the droids as far away as Anchorhead to get a transport to Mos Eisley. On the Death Star, Imperial commanders (including Grand Moff Tarkin) meet to discuss the full power of the battle station, but suspect the Rebels may find its weakness and attempt to destroy it while Tarkin announces the dissolution of the Imperial Senate and the consolidation of the political power under the Emperor with the Death Star enforcing it. One commander dismisses the threat against the supremely powerful Death Star and even dares to insult Lord Vader's caution that its power is trivial compared to the Force. Incensed at the commander's "lack of faith", Vader uses the Force to choke the commander from across the room. Tarkin orders the Dark Lord to stop, and announces his intention to have the battle station fully operational. Back on Tatooine, Ben, Luke and the droids discover dead Jawas and disorganized Bantha tracks. Ben suspects from the crudely arranged evidence that Imperial stormtroopers have ambushed the Jawas in an attempt
to find the droids and disguised it as a Tusken Raider attack. Luke then realizes that the Troopers likely learned who the droids were sold to and heads back to the Lars homestead, but after returning there he finds his family murdered and his house destroyed. Meanwhile, on the Death Star where Leia is imprisoned, Vader attempts to use an interrogation droid to extract the location of the Rebel base from her. She has managed to resist the interrogation thus far. Luke returns to the damaged Jawa Sandcrawler. Ben declares there was nothing Luke could have done had he been at the Lars homestead—Luke would too have been killed and control of the droids would have reverted to the Empire. Luke reluctantly decides to join Ben and become a Jedi. The group then heads off to Mos Eisley Spaceport to find transportation to Alderaan. As they enter Mos Eisley, several Stormtroopers accost the group, looking for C-3PO and R2-D2; however, Obi-Wan uses a Jedi mind trick to convince the Stormtroopers that the droids accompanying him "are not the droids you're looking for". Later, at a seedy bar, after an incident where Ben is forced to cow some toughs with his saber, they encounter a boastful smuggler Han Solo and his cohort Chewbacca the Wookiee. Han agrees to transport them to Alderaan with a 10,000 fee in advance, but Ben offers to pay the pirate 2,000 now and an additional 15,000 later. Solo agrees, and as Ben and Luke head out the door, the pirate is jubilant about the offer as he owes money to Jabba the Hutt for losing a loadful of spice on an earlier run when he was boarded by Imperial forces. But when he tries to leave the bar, Solo suddenly meets up with one of Jabba's goons, Greedo, who has been looking to collect a large bounty that Jabba has placed on Solo's head (for losing the shipment). Fortunately, Solo takes advantage of the fact that Greedo is foolish enough to allow his quarry to secretly reach for his gun, and shoots him from under the table. Back on the Death Star, the final inspection of the space station is completed, and the commanding officer Grand Moff Tarkin decides on a different approach to persuade Princess Leia to co-operate in revealing the location of the secret Rebel base. Tarkin orders the Death Star to set course for the planet Alderaan. As Luke, Ben, and the droids deal with selling Luke's speeder to raise the needed cash, Solo has to bargain with Jabba who is waiting for him at
Docking Bay 94 (the point of departure for Alderaan). Jabba is pacified for now with the fact that in transporting Luke and Ben, Solo has found a rich charter to pay his debt. However, the gangster warns that he will raise the bounty on the pilot's head, should he not repay Jabba as soon possible. As the old Jedi and his companions make their way to the bay, an informant summons stormtroopers. While fighting off the stormtroopers, the companions board the Millennium Falcon and make a hasty launch. After leaving the planet's surface, and dodging turbolaser fire from two orbiting Star Destroyers, the ship and its crew finally escape. Princess Leia is now brought to the Death Star's viewing room. Unable to provide the Empire with any clue to the location of the Rebel Base, Tarkin decides to test the Death Star's power on Alderaan, Leia's home planet. The princess tries to set up a ruse and tells Tarkin the Rebel Base is on Dantooine. Because Dantooine is too remote for an adequate demonstration, Tarkin destroys Alderaan anyway, as a public display of the Death Star's power. En route to Alderaan, Kenobi begins instructing Luke in the ways of the Force. Solo is skeptical, but a blindfolded Luke is able to sense the location of an attacker whilst practising with a lightsaber. In the midst of this, Kenobi is suddenly weakened by a great disturbance in the Force, the kind that the simultaneous violent deaths of millions would produce. One of the Death Star's commanders issues Tarkin a report on the fate of Dantooine: there once had existed a Rebel Base, but it is now deserted. Convinced that Leia has lied to the Imperials, Tarkin orders the Princess executed. Arriving at Alderaan, or, at least, where Alderaan should be, the crew of the Falcon is surprised to discover there's nothing there except a hail of debris. They then come upon a short-range TIE fighter and pursue it blindly up to a "small moon". They are further surprised to be hauled by tractor beams aboard what turns out to be a moon-sized space station — the Death Star. Hiding in secret smuggling compartments of their ship, they manage to evade capture, and Ben decides to attempt to disable the tractor beams holding them there. In the process, the rest of the band discover . Kenobi volunteers to disable the tractor beam while refusing Luke's offer to accompany him, with orders to stay with Han and the droids (otherwise more star systems will be in danger of the Death Star). After Ben leaves,
Luke, the smugglers and the droids learn that Leia is being held in a nearby cell awaiting execution. After some persuasion, Luke and his companions go to rescue Leia under various acts of derring-do, including a wrestling match with a tentacle-like creature in a garbage hold. After switching off the tractor beams, Kenobi encounters Vader, who attacks him. It is clear that they have known one another before, apparently in the roles of "student" and "master". Kenobi tells Vader in the clash that "If you strike me down, I will become more powerful than you can possibly imagine." When Kenobi sees that he has distracted the guards around the Falcon, which allows his friends to board it though his own escape is cut off, he allows himself to be cut down by Vader, only to mysteriously disappear at the fatal instant; Vader is seen curiously probing Kenobi's empty robes lying harmlessly on the floor. Leia, Luke, Han, Chewbacca, and the droids make their way back to the Falcon and escape, fighting off Imperial starfighters along the way. They finally reach the Rebel hideout on the fourth moon of Yavin, where they pass the plans on to the Rebel leadership. Unknown to them, but suspected by Leia, the Empire has actually allowed their escape in order to track their ship back to the Rebel Base. After General Jan Dodonna, chief stragegist for the Rebel Forces, retrieves the secret Death Star plans from R2-D2, he leads the briefing of a group of pilots who are to take on the deadly space station. A discussion ensues wherein the Rebels' plan to attack the Death Star is revealed. The tactic involves flying along a canyon-size groove in the station's surface, and firing a torpedo down a narrow ventilation shaft. The torpedo will travel to the main reactor via the ventilation shaft and start a chain reaction that will destroy the entire station. Luke is amongst the X-Wing pilots of Red Group; Han, despite Luke's pleadings, decides to leave with his reward. With time of the essence, Luke and an ad-hoc group of Rebel fighters begin their assault on the approaching Death Star. After several Rebels are killed by the power of the space station, Darth Vader suspects that several Rebel ships "have broken off from the main group" and intend to attack the Death Star ship-to-ship down the canyon leading to the reactor system. Luke and a few others make it down to the canyon, with Vader pursuing them in a distinctive, specialized TIE Fighter. Several more Rebel fighters are destroyed; one fighter makes it down the canyon, but is unable to hit the
ventilation shaft, despite the use of a targeting computer. As Luke makes his run down the canyon, he hears the unearthly voice of Kenobi, instructing him to "use the Force" to aim his torpedoes. Thus he lets go of the targeting computers of the other Rebel fighters. With the aid of Solo and Chewbacca coming back and attacking Vader's assault squad (causing a collision between Vader's fighter and a escort fighter, leaving Vader spinning out of control towards deep space), Luke successfully launches torpedoes down the shaft, destroying the Death Star and striking a huge blow for the Rebellion against the Empire. That night on Yavin IV, Luke is congratulated by his Rebel colleagues, but finds that R2-D2 has been damaged by one of Darth Vader's laser blasts. The Alliance immediately works to repair the little droid. The next day, in a civil ceremony, Princess Leia and General Dodonna award Luke and Han medals for destroying the Death Star with Chewbacca. C-3P0 and a fully repaired R2-D2 are in attendance, dancing joyously on the dais.