With the sound of the Sand People approaching, they decide to find safety elsewhere. The damaged C-3PO (with a broken detached arm) and the other droid are put in the landspeeder with Luke and Ben to travel to Kenobi's small desert dwelling. While Luke repairs his droid, he speaks with Ben, denying that his father was ever a Jedi, an heroic warrior-guardian from ancient times who preserved order in the universe: "My father didn't fight in the wars. He was a navigator on a spice freighter." Then, he learns that his uncle told him a lie to keep it a secret from him because "he didn't hold with your father's ideals." Luke is told that Ben is the last living member of a planetary Round Table known as the Jedi Knights: "I was once a Jedi Knight. The same as your father." Luke learns that his father fought in the Clone Wars and was indeed a Jedi, the "best star pilot in the galaxy and a cunning warrior. I understand you've become quite a good pilot yourself. And he was a good friend."

Now that Luke is old enough, Ben goes to his chest and removes a small sword handle to give Luke something his father has passed down to him. According to Ben, Luke's uncle wouldn't allow it and feared that Luke "might follow old Obi-Wan on some damn-fool idealistic crusade like your father did." Kenobi explains the laserbeam light-saber/sword, the weapon of the Jedi Knight:

An elegant weapon, for a more civilized age. For over a thousand generations the Jedi Knights were the guardians of peace and justice in the old republic - before the dark times. Before the Empire.

Luke wants to know more and learns how his father died, finding a justifiable motive for avenging his father's death:

Luke: How did my father die?
Ben: A young Jedi named Darth Vader, who was a pupil of mine until he turned to evil, helped the Empire hunt down and destroy the Jedi Knights. He betrayed and murdered your father. Now the Jedi are all but extinct. Vader was seduced by the dark side of the Force.
Luke: The Force?
Ben: Now, the Force is what gives a Jedi his power. It's an energy field created by all living things. It surrounds us, it penetrates us, it binds the galaxy together.

Ben activates R2-D2's message. Together, they see the holographic image of the beautiful girl and listen to the entire message from Princess Leia, telling about how the stored secret Death Star plans inside R2-D2 must be delivered to her father on Alderaan:

General Kenobi. Years ago, you served my father in the Clone Wars. Now he begs you to help him in his struggle against the Empire. I regret that I am unable to present my father's request to you in person. But my ship has fallen under attack and I'm afraid my mission to bring you to Alderaan has failed. I have placed information vital to the survival of the rebellion into the memory systems of this R2 unit. My father will know how to retrieve it. You must see this droid safely delivered to him on Alderaan. This is our most desperate hour. Help me Obi-Wan Kenobi. You're my only hope.

Ben tugs at his beard, turns to Luke and advises: "You must learn the ways of the Force if you're to come with me to Alderaan." Luke is uncertain about getting involved in the mission, insisting that he is already in trouble with his uncle who needs him at home to help with the harvest: "Alderaan? I'm not going to Alderaan." Ben needs new blood to continue the fight against the Empire: "I need your help, Luke. She needs your help. I'm getting too old for this sort of thing." When Luke only offers excuses, Ben reminds Luke: "That's your uncle talking."

Ben encourages him: "Learn about the Force, Luke." Luke reluctantly decides to help only in a small way by transporting him to the local spaceport at Anchorhead: "Look, I can take you as far as Anchorhead. You can get a transport there to Mos Eisley or wherever you're going." Ben accepts with a wily grin: "You must do what you feel is right, of course."

Seated around a large conference table on the fearsome Death Star battle station light years away, the evil Galactic Empire is led by the vicious tyrant, the skeletal Grand Moff Tarkin (Peter Cushing), Governor of the Imperial Outland Regions, whose power-mad goal to dominate every planet within his reach is nearing completion: "The Imperial Senate will no longer be of any concern to us. I have just received word that the Emperor has dissolved the Council permanently, the last remnants of the old Republic have been swept away." One of the officers is concerned about their vulnerability, possible danger to the Death Star and other challenges posed by the Rebels. The Grand Moff's right-hand second-in command, Darth Vader, assures everyone that the stolen plans for the Death Star will soon be back in their hands. Another officer, General Motti (Richard LeParmentier) is confident: "Any attack made by the Rebels against this station would be a useless gesture, no matter what technical data they've obtained. This station is now the ultimate power in the universe. I suggest we use it."

But Darth Vader warns of the awesome power of the Force:

Don't be too proud of this technological terror you've constructed. The ability to destroy a planet is insignificant next to the power of the Force.

The officer sneers back at Vader, mocking him: "Don't try to frighten us with your sorcerer's ways, Lord Vader. Your sad devotion to that ancient religion has not helped you conjure up the stolen data tapes, or given you clairvoyance enough to find the Rebel's hidden fortress..." Raising one black armored fist, Darth gives the skeptical officer a demonstration of the powers of the Force. He commands the mystical, evil power of the Force to telekinetically strangle the officer: "I find your lack of faith disturbing." Tarkin commands Vader to release the choking grip: "Enough of this! Vader, release him!" Vader complies and the officer collapses.

The Death Star threatens to rule the galaxy as the greatest and most developed weapon and threat. The Grand Moff assures everyone that Vader will succeed in obtaining the plans and destroying the Rebels: "Lord Vader will provide us with the location of the Rebel fortress by the time this station is operational. We will then crush the rebellion with one swift stroke."

On their return, Ben and Luke discover the blasted, grisly remains of an attack on the Jawa's sandcrawler transport, owned by: "the same Jawas that sold us Artoo and Threepio." On the ground are the bodies of the dead Jawas. Kenobi knows that the destruction was not caused by the Sand People: "These blast points - too accurate for Sand People. Only Imperial stormtroopers are so precise." Suddenly, it dawns on Luke that his relatives are in danger: "If they traced the robots here, they may have learned who they sold them to, and that would lead them back...home!" After Luke speeds home in his landspeeder, he sadly finds the two, incinerated charred skeletons of his aunt and uncle, and their farm has been burned to the ground. Darth Vader's Imperial Forces have already visited in a deadly search for the plans.

Meanwhile, in a dungeon cell within the Death Star, Vader is escorted by Imperial soldiers to enter imprisoned Princess Leia's cell, where he questions her about the location of the hidden Rebel base, threatening robotic torture with a cruel-looking, black, round floating device with sharp needles, containing truth serum. The Princess recoils in fear as they prepare her torture.

Soon, Luke returns to Ben and the droids at the site of the ravaged sandcrawler, where they are burning the bodies of the dead Jawas. Ben comforts Luke, reminding him that he also would have been killed if he had been at home, and that he would have been powerless against the Imperial stormtroopers. Luke has already changed his mind, deciding to accompany Ben to Alderaan, and angrily vowing vengeance for the deaths of his aunt and uncle: "I want to come with you to Alderaan...I want to learn the ways of the Force and become a Jedi like my father."

Luke joins Ben (and the robots) and travels with him in the landspeeder to Mos Eisely, Tatooine's spaceport in a distant province. On a high ridge overlooking the city, Ben warns them to be careful, describing it as a "wretched hive of scum and villainy." At the edge of the city, several white-armored Imperial Force stormtroopers detain them and demand their identification. Ben uses the Force's mind-controlling power to avoid questioning about their droids: "You don't need to see his identification." Trance-like, the trooper repeats his words: "We don't need to see his identification...These aren't the droids we're looking for...You can go about your business...Move along." Luke is incredulous and asks: "I can't understand how we got by those troops. I thought we were dead." "The Force can have a strong influence on the weak-minded," Ben casually explains.

They are searching for a space pilot for-hire who will take them to Alderaan. In one of the film's most humorous and memorable scenes, they enter a dark saloon/cantina populated by bizarre space creatures from all corners of the galaxy. An alien jazz band plays in the spacebar, and other cutthroat lifeforms and creatures sit at tables or at the bar, drinking. The droids are refused service and must remain outside: "We don't serve their kind here." At the bar, two brutal bar thugs (a bulb-eyed alien and a burn scarred-faced human) purposely taunt and threaten Luke: "You just watch yourself. We're wanted men. I have the death sentence on twelve systems." Ben appears at young Luke's side to defend him: "This little one's not worth the effort." But when forced to, Ben ignites his lightsaber and swiftly and fluidly slashes the arm off one of the villains. From then on, they are left alone by the remaining cantina customers. Outside the spacebar, the two droids watch a man from inside the bar come out and tell two Imperial troopers what he has just witnessed inside the cantina.

At one of the corner tables, Ben and Luke discuss their need to find passage to Alderaan with a Corellian smuggler named Han Solo (Harrison Ford). Solo, the pilot of a ship named the Millennium Falcon is joined by his first mate, co-pilot partner, a large, seven-foot furry Wookie/anthropoid named Chewbacca (Peter Mayhew) (similar in character to the Cowardly Lion in The Wizard of Oz). Han brags about the speed of his ship: "You've never heard of the Millennium Falcon?...She's fast enough for you, old man." Ben demands that "no questions (are) asked," to "avoid any Imperial entanglements." Han suggests being paid a mercenary price to be their pilot:

Han: Ten thousand, all in advance.
Luke: Ten thousand! We can almost buy our own ship for that.
Han: But who's going to fly it, kid? You?
Luke: You bet I could. I'm not such a bad pilot myself...
Ben: We can pay you two thousand now, plus fifteen when we reach Alderaan.
Han: Seventeen, mmm. OK. You guys got yourselves a ship. We'll leave as soon as you're ready. Docking Bay Ninety-Four.

Solo is relieved that he will be paid handsomely - 17,000. Soldiers enter the bar and question the bartender about the lasersword fight. Ben and Luke quickly slip out, as Solo sends Chewbacca to the ship to quickly prepare for departure. Out on the street, Ben and Luke sell their landspeeder to provide their first payment installment for their journey to Alderaan.

Just as Solo leaves, he is stopped by a green-skinned, lizardy bounty hunter named Greedo who has finally found his valuable target and points his gun at Solo: "Going somewhere, Solo?" Solo is heavily in debt to Greedo's boss named Jabba and tries to explain: "Yes, Greedo. As a matter of fact, I was just going to see your boss. Tell Jabba that I've got his money." Greedo tells Solo that it's already too late - a high price has been placed on his head and "every bounty hunter in the galaxy" is looking for Solo. During their discussion at a cantina table, Han carefully releases his holstered weapon out of view under the table and then fires at the alien with an explosive flash of light. The green creature falls forward onto the table, dead. Strolling out of the bar, Solo gives the bartender some money to clean up: "Sorry about the mess." He flees to his ship, where the fat, slug-like Jabba the Hutt, a crime lord with a gang of pirates, including another bounty hunter named Boba Fett (Mark Austin), demands a long-overdue payment (with 15% interest). Han promises payment but asks for a little more time to earn the money from the chartered trip to pay his debt.

Aboard the Death Star, Princess Leia's resistance to Darth Vader's mind probe is considerable, and he is delayed in extracting any information about the location of the Rebel Forces from her. The Death Star's commander Grand Moff Tarkin suggests: "an alternative form of persuasion...demonstrating the full power of this station." He orders his navigators: "Set your course for Alderaan."

Hurrying on their way to the docking bay, Luke, Ben and the droids are unaware that they are being followed, and that their location is being reported to Imperial soldiers. When they reach Docking Bay 94, Luke reacts to Solo's rattle-trap ship: "What a piece of junk!" Solo boasts of its speed: "She may not look like much, but she's got it where it counts, kid. I made a lot of special modifications myself. But we're a little rushed, so if you'll just get on board, we'll get out of here." As they prepare to take off, the tipped-off Imperial Force guards rush into the docking bay where a gunblaster battle is fought. Han holds the forces off while Chewbacca prepares for their launch. At the last moment, Han rushes on board, they buckle up, and then blast off into the blue sky from Mos Eisley.

In the cockpit, Han and the Wookie work on the controls as they are pursued by an Imperial Force cruiser and other ships. To evade them and escape capture, they angle the deflector shields as Solo makes calculations to jump into light speed (faster-than-light hyperspeed). Luke is still unimpressed and doubts the ship's capabilities as the ship is pounded by turbolaser fire from the pursuit of the Star Destroyers:

Luke: Why don't you outrun them? I thought you said this thing was fast.
Han: Watch your mouth, kid, or you're going to find yourself floating home. We'll be safe enough once we make the jump to hyperspace. Besides, I know a few maneuvers. We'll lose them. Here's where the fun begins.
Ben: How long before you make the jump to lightspeed?
Han: It'll take a few moments to get the coordinates from the navicomputer.
Luke: Are you kidding - at the rate they're gaining?
Han: Traveling through hyperspace isn't like dusting crops, boy.

In a spectacular special effects sequence when they jump into the safety of hyperspace, the ship's acceleration roars as stars blur and splinter in their view into brilliant streaks of white light.

Moving into the Alderaan system with the Death Star, the Grand Moff Tarkin plans to test the power of the Death Star by destroying Leia's home of Alderaan, a small bluish-green planet in space. In the control room, he explains his revenge to the Princess, because she refuses to reveal the locations of other space rebels.

Princess: Governor Tarkin, I should've expected to find you holding Vader's leash. I recognized your foul stench when I was brought on board.
Grand Moff Tarkin: Charming to the last. You don't know how hard I found it signing the order to terminate your life.
Princess: I'm surprised you had the courage to take the responsibility yourself.
Grand Moff Tarkin: Princess Leia. Before your execution, I would like you to be my guest at a ceremony that will make this battle station operational. No star system will dare oppose the emperor now.
Princess: The more you tighten your grip, Tarkin, the more star systems will slip through your fingers.
Grand Moff Tarkin: Not after we demonstrate the power of this station. In a way, you have determined the choice of the planet that is to be destroyed first. Since you are reluctant to provide us with the location of the Rebel base, I have chosen to test this station's destructive power on your home planet of Alderaan.
Princess: No! Alderaan is peaceful. We have no weapons. You can't possibly...
Grand Moff Tarkin: You would prefer another target, a military target? Then, name the system! I grow tired of asking this, so it will be the last time. Where is the Rebel base?

The Princess agonizes and then divulges the location of the Rebel base - it is on Dantooine in a different planetary system. Thinking that she has told the truth, the ruthless, untrustworthy Grand Moff Tarkin double-crosses her and orders the operation against Alderaan to proceed anyway, since he still needs to test the Death Star. "You're far too trusting," he tells the Princess. In her horrified and pained view, the bluish-green planet Alderaan is blown to pieces by a powerful superlaser. The Rebel base at Dantooine is the next target to be destroyed.

On board the Millennium Falcon, Luke practices with his Jedi lightsaber, guarding himself against a hovering remote. Mystically connected with the Force, Ben's body weakens at the moment of Alderaan's destruction: "I felt a great disturbance in the Force, as if millions of voices suddenly cried out in terror and suddenly silenced. I fear something terrible has happened."

While Luke continues his exercises, the Wookie plays a game of chess (with miniature, holographic, animated chess pieces / fantastic creatures) against opponent R2-D2. Han Solo warns that Wookies are sore-losers:

Han: Let him have it. It's not wise to upset a wookie.
C-3PO: But sir. Nobody worries about upsetting a droid.
Han: That's cause a droid don't pull people's arms out of their sockets when they lose. Wookies are known to do that.
C-3PO: I see your point, sir. I suggest a new strategy, R2. Let the Wookie win.

Luke practices with the lightsaber, deflecting pulses from a small, hovering remote sphere, but missing. Ben mentors Luke, reminding him during his exercises to rely on the instinctual responsiveness of the Force rather than his conscious self:

Ben: Remember, a Jedi can feel the Force flowing through him.
Luke: You mean it controls your actions?
Ben: Partially, but it also obeys your commands.
Han (after laughing): Hokey religions and ancient weapons are no match for a good blaster at your side, kid.
Luke (to Han): You don't believe in the Force, do you?
Han: Kid, I've flown from one side of this galaxy to the other. I've seen a lot of strange stuff, but I've never seen anything to make me believe there's one all-powerful Force controlling everything. There's no mystical energy field controls my destiny! It's all a lot of simple tricks and nonsense.
Ben: I suggest you try it again, Luke. This time, let go your conscious self and act on instinct.

Ben places a helmet on Luke's head with the blast-shield down to blind him, telling him: "Your eyes can deceive you. Don't trust them. Stretch out with your feelings." Luke calmly evades and deflects three pulses from the remote, successfully using the Force. Skeptically, Han calls it luck. Ben believes otherwise: "In my experience, there's no such thing as luck." But Han disagrees: "Look. Good against remotes is one thing. Good against the living...that's something else." Ben congratulates Luke: "You've taken your first step into a larger world." Solo announces that they are approaching Alderaan.