The Rebel Alliance has just achieved its first real victory against the Galactic Empire, stealing the plans for its moon-sized, planet-destroying space station named the Death Star. They're now under the care of the high-ranking Rebel leader Princess Leia Organa on her ship the Tantive IV, but Emperor Palpatine's personal protégé Darth Vader, is in hot pursuit, and his forces catch up and board the ship over the planet Tatooine. The Imperial Stormtroopers mow down the Rebel soldiers, and caught in the middle are astromech droid R2-D2 and protocol droid C-3PO, who are briefly separated in the chaos.
As it becomes clear there will be no way to escape, Leia uploads the plans into R2-D2 shortly before C-3PO finds him again. She then gets a shot off at a Stormtrooper before being stunned and brought to Vader. She tries to stick to her cover story of being an Imperial senator from Alderaan, but Vader sees right through it (not least because he just personally witnessed this ship escaping with the tapes, which he's polite enough to not point out). R2-D2 manages to get to an escape pod, with C-3PO following despite his constant grumbling about the danger they're getting into, which R2-D2 isn't helping by insisting he has a secret mission. The gunner on the Star Destroyer lets the pod go because there aren't any life signs from the droids (and thus becomes the most important character in the entire franchise).
After landing on Tatooine, C-3PO continues getting annoyed at R2-D2's mission, and when they disagree on a direction to go, he insists on going off on his own. He soon comes to regret it as he just ends up further in the endless desert, but then spots a transport in the distance and calls to him. On his own route, R2-D2 ends up going through a canyon where he's ambushed by Jawas, who disable him and load him into their massive Sandcrawler to be sold. It also turns out this is the same transport that C-3PO spotted, and the two are reunited.
The Jawas set up shop at the moisture farm of Owen and Beru Lars, who are assisted by their nephew Luke Skywalker, a callow and immature young man obsessed with escaping the dreary desert planet and joining the rebellion like many of his friends have already done. Owen is quickly convinced to buy C-3PO, but selects another astromech than R2-D2. But the separation is short-lived as within seconds the other astromech breaks down (and if you go by the radio adaptation, R2-D2 actually sabotaged it). C-3PO promptly recommends R2-D2 instead, and they're able to stay together.
As Luke cleans the family's new acquisitions, he's fascinated when C-3PO reveals they were previously owned by Rebel leader Captain Antilles. He then accidentally activates a message Leia recorded for R2-D2, though only the last few seconds keeps playing on a loop: "Help me, Obi-Wan Kenobi. You're my only hope." Luke has never heard of him, but says a strange desert-dwelling hermit named Ben Kenobi might be a relative. R2-D2 suggests his restraining bolt be removed so he can play the full message, but upon Luke doing it he shuts it off and denies even remembering it. Luke is called to dinner, where he's angered that Owen asks him to delay going to the Imperial Academy another year. He storms off to stare at the dual sunset he'll apparently be looking at for the rest of his life, while Owen and Beru darkly hint at their true worry.
- Beru: Luke's just not a farmer, Owen. He has too much of his father in him.
Owen: That's what I'm afraid of.
Luke returns to the droids but finds only C-3PO, cowering in the corner as he reports that with his restraining bolt off, R2-D2 has run into the desert still talking about his secret mission. The nearby Tusken Raiders make it too dangerous to search now, and he's forced to wait until morning. Upon setting out in his landspeeder, Luke and C-3PO quickly find R2-D2, but they're also attacked by the Tusken Raiders, and Luke can only make a couple desperate dodges of their blows before he faints, likely saving his life as the Raiders lose interest and turn to looting his speeder. However, they're scared off by an eerie whistling noise, soon revealed as the work of Ben Kenobi.
Luke wakes up and explains about the message, and Ben reveals he is in fact Obi-Wan, a name he hasn't used since before Luke was born (just a slight bending of the truth compared to certain other things he'll be saying). They retreat to Obi-Wan's house before the Raiders return, and the old man explains that he was once a Jedi Knight, the "guardians of peace and justice" before they were nearly wiped out by the Empire. And another of the Jedi was Luke's father Anakin, which Owen and Beru have kept hidden from him. Obi-Wan sadly goes on that his former pupil Darth Vader "betrayed and murdered your father" after being seduced by the dark side of the Force, the energy field surrounding all living things which is the source of the Jedis' power. Finally, he presents Luke with his father's lightsaber, the Jedi weapon which uses kyber crystals to create a sword blade of pure energy. Obi-Wan is also able to find Leia's complete message, in which she explains about her mission to deliver the Death Star plans to her father Bail on Alderaan, and now calls on Obi-Wan as her only hope to finish the mission due to his serving with Bail in the Clone Wars. Obi-Wan promptly says that Luke should come with him to Alderaan as he's too old now to finish the mission on his own, but Luke insists that he needs to stay and help on the farm.
Unfortunately, the choice is soon made for him, as on the way back to the farm they find the Jawas slaughtered, and Obi-Wan points out that the precise blast points on the sandcrawler indicate it was Imperial Stormtroopers (whether this is another Jedi lie is up to you). Luke quickly puts the pieces together that the Stormtroopers were tracking the droids and races back home, only to find it a smoking ruin and his aunt and uncle reduced to skeletons in the rubble. He returns and somberly declares there's nothing left for him on Tatooine, and he wants to join Obi-Wan's mission and be trained as a Jedi like his father.
On the Death Star, the Imperials are growing frustrated with Leia's continued resistance to telling them where the Alliance's main base is. The project leader Grand Moff Wilhuff Tarkin brags that they'll be able to destroy the rebels in a single stroke with the station, to which Vader cautions him that even the ability to destroy a planet pales in comparison to the Force. Admiral Motti scoffs at this, insulting Vader's religion which hasn't led him to the rebel base either. Vader then shows the full power of the Force, causing Motti to choke with simply a thought while dryly saying "I find your lack of faith disturbing." The admiral is only saved by Tarkin insisting Vader let him go.
Obi-Wan takes Luke to where they can get transport to Alderaan, though he doesn't have the highest opinion of the place.
- Obi-Wan: Mos Eisley Spaceport. You will never find a more Wretched Hive of scum and villainy. We must be cautious.
While passing through the town, the group is stopped by some Stormtroopers. But when all seems lost, Obi-Wan simply starts telling them R2-D2 and C-3PO are not the droids they're looking for and they should be able to keep going, and the leader simply repeats it all and lets them go. Obi-Wan explains this to the shocked Luke as another ability of the Force.
They enter the town's Cantina to find a pilot who'll carry them, and are greeted with a stunning menagerie of aliens. But droids still turn out to not be allowed and R2-D2 and C-3PO quickly agree to wait outside. At the bar, Luke is accosted by crooks Cornelius Evazan and Ponda Baba, who aggressively try to pick a fight even with Obi-Wan trying to talk them down. With no other option, he whips out his own lightsaber and cuts Baba's arm off (and to think they managed to escape the destruction of Jedha just for this).
Obi-Wan has also found a likely candidate with Han Solo and his Wookie co-pilot Chewbacca. The arrogant, sleazy smuggler doesn't endear himself much to Luke, especially with his blatant price gouging once it becomes clear how desperate they are, but Obi-Wan still manages to cut a deal to sell Luke's speeder for a down payment on even more than Han was asking. As they leave to make preparations, Han is accosted by bounty hunter Greedo, who reveals that the local crime lord Jabba the Hutt has lost patience on Han repaying the debt he owes for jettisoning Jabba's cargo, and has put a price on his head. Han banters a bit before covertly getting his blaster out and blowing the hapless bounty hunter away (and Greedo most definitely does not get a shot off first) before getting the drop on Jabba and promising to pay him back for the lost cargo with 15% interest once he gets his pay for a transport he's about to undertake for a couple of locals wanting passage to Alderaan.
By now, some Imperial spies in town have reported on the suspicious new arrivals, and they have to make a quick getaway. Luke is quite unimpressed with Han's ship the Millennium Falcon, blurting out "What a piece of junk!", but Han insists she comes through where it counts, and soon some Stormtroopers arrive to force the issue. They get the ship into space, but a pair of Star Destroyers are on their tail and it takes Han and Chewbacca a tense couple minutes to make calculations for a jump to lightspeed that won't have them slamming into any obstacles. Luckily, the ship comes through just as he said and they leave the Imperials in the dust.
After Leia's continued resistance, Tarkin has Vader bring her to the bridge so he can deal with her personally. Leia keeps the sass up:
- Leia: Governor Tarkin, I should have expected to find you holding Vader's leash. I recognized your foul stench the moment I was brought on board.
Tarkin shuts her up by revealing that in the absence of a rebel base to demonstrate the Death Star's power on, he's instead going to destroy her home planet. Leia protests that Alderaan is a peaceful planet with no weapons, and finally breaks down as she says the base is on Dantooine. However, Tarkin goes back on his word and orders Alderaan destroyed anyway, and Leia is forced to watch as her home and everyone on it is destroyed.
On the Millennium Falcon, Luke has started his training by using his lightsaber to block shots from a remote training droid. Suddenly Obi-Wan keels over:
- Obi-Wan: I felt a great disturbance in the Force, as if millions of voices cried out in terror and were suddenly silenced. I fear something terrible has happened.
He pushes on with Luke's training, having him put on a helmet with the blast shield lowered so he'll have to rely on the Force rather than sight. After a couple failures he actually manages to block some shots, but Han remains skeptical, saying he's never seen anything in his travels to convince him something like the Force exists (one wonders what he thought of those stories about the Jedi before they were wiped out when he was around twelve years old).
Tarkin is informed that the remains of a rebel base were found on Dantooine, but it's long been abandoned. While Vader gloats over his superior's own failure to break the princess, Tarkin loses all patience and simply orders her execution.
The Falcon reaches Alderaan, but of course there's nothing to find except an asteroid field. As the full weight of this hits everyone, an Imperial TIE fighter swoops past them, appearing to head for a moon in the distance, before Obi-Wan realizes the truth.
- Obi-Wan: That's No Moon, it's a space station.
Han desperately tries to break away, but they've already become caught in the Death Star's tractor beam and are helplessly pulled inside it.
Vader personally comes out to examine the mysterious ship that was brought in, and senses the presence of his old master Obi-Wan, which so disturbs him that he storms off without finishing his sentence. As the Falcon is searched, the team hides out in hidden compartments under the floor that Han installed for smuggling. They also trick some Stormtroopers into an ambush and steal their uniforms, allowing them to break into a communication center and blast all the crew inside. R2-D2 taps into the computer to find the controls for the tractor beam, which Obi-Wan elects to take care of. After he leaves, R2-D2 also discovers that Leia is onboard and due to be terminated. Luke insists they rescue her, and when Han refuses to risk his skin for a stranger, Luke gets him on board by appealing to his basest instincts, pointing out Leia is rich and will be inclined to reward him for saving her. C-3PO and R2-D2 are left behind, only being told to lock the door and "hope they don't have blasters" if anyone comes by.
Luke and Han enter the detention center in their Stormtrooper uniforms claiming to be transferring Chewbacca between cells. But they've left his wrist binders unlocked, and with the element of surprise make quick work of the guards while also shooting out all the surveillance devices in the room. The desk gets a call due to the noise, and Han's pitiful attempts to stall an investigation just sound more suspicious. Luke opens Leia's cell, forgetting he's still in full armor:
- Leia: Aren't you a little short for a Stormtrooper?
After explaining he's come with Obi-Wan to rescue her, the reinforcements arrive and everyone takes cover in the cells. Leia, badass that she is, is quite unimpressed by her rescuers and takes over the operation herself, blasting open a garbage chute for everyone to escape.
3PO and R2-D2 are discovered, but easily claim to be Imperial droids who were imprisoned in a side room, and leave for the main hangar.
Upon landing in the garbage container, Han tries to blast through the door, only for the shot to ricochet around the room and get him a good yelling-at from both Luke and Leia. Things get worse when it turns out a vicious Dianoga is living in the container, and pulls Luke under the water. All their attempts to fight it off aren't very effective, but after a while it leaves on its own because the compactor has been activated! Luke tries to call C-3PO to turn it off, but the tension rises as he'd turned off his commlink while talking to the Imperials until R2-D2 reminds him about it. He turns it back on just in time for R2-D2 to shut the compactor down, though he does briefly confuse their jubilation at being saved for screams of agony.
After R2-D2 and C-3PO open the door, the group doesn't make it far before running into more Stormtroopers. Han chases after the group all on his own, until running into a much larger group that turns the tables, before he and Chewbacca escape thanks to a badly timed order to close the blast doors. Luke and Leia have their own narrow escape involving swinging over a giant chasm, before everyone meets up again at a window overlooking the Falcon.
Obi-Wan has successfully shut the tractor beam down, but encounters Vader himself just outside the hanger.
- Vader: The circle is now complete. When I left you, I was but the learner. Now I am the master.
Obi-Wan: Only a master of evil, Darth.
They whip out their lightsabers and engage in a fight that's just as slow and painful as you'd expect between an old man and a half-machine. But Obi-Wan still retains his serenity, because:
- Obi-Wan: You can't win, Darth. If you strike me down, I shall become more powerful than you can possibly imagine.
The fight distracts the Stormtroopers guarding the Falcon so everyone rushes over, but Luke is distracted when he also sees the two. Obi-Wan smiles at him, then turns back to Vader and allows the fatal blow. Luke goes berserk and starts shooting at the Stormtroopers, until Obi-Wan's voice tells him to run. Meanwhile, Obi-Wan's body vanished at the moment of his death, and Vader prods at his empty cloak in confusion.
Back on the Falcon, Luke barely has time to grieve before four TIE fighters come after them. Luke and Han manage to take down all of them, but Leia maintains that the fight isn't over as they have to get the plans inside R2-D2 to the Rebellion and find a weakness in the Death Star, now under much more of a time crunch since there's doubtlessly a tracking device on the Falcon. Han insists that he's finished the job he was hired for and expects to leave with his payment. Leia is so miffed she even snaps at Luke, which doesn't stop Han wondering if someone like him could make it work with her, which Luke quickly denies.
The Falcon arrives at the Rebel headquarters on Yavin IV, where Luke is delighted to meet back up with his old friend Biggs Darklighter, one of those who got to the academy before him. The Death Star plans are analyzed, and it's discovered that a proton torpedo shot down a tiny exhaust vent will create a chain reaction that will ultimately destroy the station (again, see this movie for how such a design flaw made it into the station).
As the Rebels prepare for battle, Luke is disappointed to see Han packing up his reward. He again says he was never in this mission for anything but the money, and fighting the Death Star is more like suicide than bravery. Though he does sincerely tell Luke "May the Force be with you" as he leaves. Luke boards an X-Wing fighter and insists on R2-D2 being his wingman despite his damage. In stark contrast to his complaining up to now, C-3PO asks R2-D2 to take care of himself, as "You wouldn't want my life to get boring, would you?"
The Death Star arrives, and the race is on to take it down before it clears Yavin and has a shot at the moon. As predicted, the small fighters are easily able to avoid the station's canons, forcing the Imperials to send out their own ships, Vader himself included. Many of the Rebels are killed, and even when fellow X-Wing pilot Wedge Antilles lines up a perfect shot according to his computer, it fails to enter the vent. Eventually even Biggs is shot down and killed, while Wedge is forced to withdraw when his fighter is damaged. Inside, Tarkin is urged to leave the station on the off-chance they're defeated, but arrogantly declares it impossible.
Luke begins his own run with Vader and two other TIE fighters on his tail. As he approaches the target, Obi-Wan's voice appears again and tells him to use the Force rather than his computer. Vader himself is impressed at how strong the Force is in him, but still is able to take out R2-D2. But just when all seems lost, more shots come from behind the TIE fighters, sending Vader tumbling away from the battle while the other two are destroyed. Luke is amazed to hear his rescuer is none other than:
- Han: You're all clear, kid! Now let's blow this thing and go home!
Sure enough, with the help of the Force Luke is able to send his torpedoes down the shaft and he, the Falcon, and the few other Rebels who survived the battle fly away as behind them the Death Star explodes in spectacular fashion. Luke receives one final message from Obi-Wan:
- Obi-Wan: The Force will be with you, always.
Back at the Rebel base everyone revels in their success and Han is happily welcomed to the cause. The mood is interrupted when the badly damaged R2-D2 is removed from the X-Wing, with C-3PO beside himself and offering to donate any parts that could help.
Later on, the new heroes of the Rebellion are decorated by Leia, the ceremony attended by all the survivors, including a gleaming clean C-3PO who reveals that R2-D2 has been successfully repaired. Luke and Han are given medals, and Chewbacca roars to the crowd (popularly believed to mean "Where the hell's my medal?"). The war is far from over, and the Empire will strike back, but the Rebels are in their best position in ages having received their New Hope.