The Tiger Moth, a flying pirate ship commanded by a pink-haired woman called Dola (voice: 克萝丽丝·利奇曼 in the Disney English dub) and manned by her seven or eight grown sons, spots a larger flying ship, from which a girl looks out a window. The men in the cabin with the girl wear dark suits and dark glasses (which is odd, as its dark outside). The men seem to recognize the pirates, who have apparently been lying in wait. They attack using small four-winged chariot-like fliers called flapters, dropping from the flapters to the top of the larger ship. Once inside, the pirates run through a crowd in a spacious glass-walled cabin—there's a party going on—and trade gunshots with some of the dark-suited men. Dola shouts "I want that girl!"
The leader of the dark suits enters the girl's cabin, and calling her Sheeta (voice: 安娜·帕奎因), tells her to stay out of the way. He opens a suitcase that holds a transmitter and starts sending a message in Morse code. While he's occupied, Sheeta knocks him out with a wine bottle, reaches inside his jacket and from an inner pocket pulls a necklace, which she puts on. There's knocking and shouting outside the door, so she opens the window, climbs out, and clings to the side of the plane. The pirates burst into the room and recognize the unconscious man, Muska (voice: 马克·哈米尔). They nearly miss the girl, but one thinks to look out the window and spots her. Dola notices that she's wearing the necklace, and says "I want that crystal!"
Sheeta inches over to the next window, but one of the pirates gets into the room and rushes the window; she falls. "There goes my crystal!" wails Dola. Sheeta disappears into a cloud.
The opening credits show steampunk industrial scenes of mining, building flying machines, and islands floating in the sky.
Sheeta falls from the clouds and hurtles toward the ground, head-first and unconscious. Her crystal lights up and she falls more slowly, turning so she's lying face-up. She seems to be asleep and falling toward a lighted town; it's still dark.
On the ground, working-class folk in 19th-Century European clothes are shopping and talking. A boy (voice: 詹姆斯·范德比克) comes into a shop and asks for some meatballs for his boss. The man behind the counter, calling the boy Pazu (pronounced pot-zu), is surprised that the boy is still working at this hour.
Running back to work, the boy sees something falling from the sky, realizes it's a person, and catches Sheeta as she floats down into the open shaft of a mine. From down in the hole the mine boss (voice: John Hostetter) irately calls for his dinner, and is too busy with his malfunctioning machinery to listen when Pazu tries to tell him about the girl who came down from the sky. Pazu leaves Sheeta, still sleeping, on a platform near the top of the mine shaft and goes back to work. He operates the elevator hoist by himself for the first time, bringing up a crew of miners and their haul for the day, a small cartload of coal. They complain about not finding any silver or even tin. The boss, predicting that they'll all be starving soon, asks Pazu to shut off the boiler and oil the machinery, and goes home for the night.
Dola has returned to her ship, but her sons are out searching for Sheeta in their flapters. One complains there's too much cloud cover and it's too dark, but Dola won't call off the search. She tells them to call her captain, and they reply "yes, Mom," in unison.
The Legend of the Castle in the Sky
Next morning, Pazu wakes up at home—he slept on the floor—and sees Sheeta, still asleep in his bed. He climbs through a skylight to the roof and opens a window in a brick tower attached to his small wooden house, releasing some white doves. Then he climbs to the top of the tower and plays his trumpet. Pazu's house is perched on the lip of a cliff, and is part of a larger building that's mostly in ruins.
The trumpet wakes Sheeta, who climbs the ladder to the roof, following the music. Pazu shakes her hand and introduces himself, then gives her some food to feed the doves. She's surprised to hear from Pazu that he found her floating in the air; she remembers being in an airship, but nothing more. Pazu has a theory about how she can float; he asks to see her necklace. She hands it to him and says her grandmother gave it to her and it's been in her family for generations. The crystal is blue with a gold symbol. Pazu puts on the necklace and jumps off the roof. He doesn't float. Sheeta finds him in a hole; he's broken through a terrace into his own basement. The room is set up as a workshop, with the wooden framework of a plane in the middle of the floor. When Pazu goes back upstairs to see to breakfast, Sheeta notices a photograph on the wall that looks like an island or a fortress surrounded by clouds. Its captioned "Laputa."
Pazu finds her looking at the picture and says his father, who loved to fly, took it from an airship. He explains that most people think Laputa, the island that floats in the sky, is a legend. There's also a picture of Pazu's father's airship, and his journal, with drawings of the castle on the floating island. But nobody believed he'd seen it, and Pazu thinks that being called a liar killed his father. He says that as soon as he finishes building his plane, he'll prove that Laputa is real.
Beware of the Pirates
Sheeta sees a car pull up outside, and Dola looks out. Sheeta backs away from the window while Pazu exclaims "a real automobile! You don't see many of those around here!" Sheeta says the people in the car are pirates, and they attacked her airship. The pirates are much better dressed than they were the night before and look quite respectable, but Pazu immediately accepts that they're pirates and they're after Sheeta.
When the pirates come to the door, Pazu runs out, accompanied, apparently, by another boy. He stops when asked if he's seen a girl and says "there are about 100 little girls in this town—which one?" He and Sheeta run off as the second pirate, who went around and got in the back of the house, comes out holding Sheeta's bluish-purple dress and saying she must be in disguise now.
On the village street, a pair of pirates in white suits are asking Pazu's boss about a little girl in pigtails and a purple dress. When he says he hasn't seen her, Pazu can be heard in the distance shouting "Boss! Boss!" As Pazu and Sheeta come running up the street, the pirate Shalulu (voice: 迈克尔·麦克沙恩) urges the boss to think harder, saying "she would be about the age of those two." Sheeta trips and falls, dislodging her borrowed cap and exposing her pigtails. The pirates try to grab her but Pazu and Sheeta take refuge behind the boss; Pazu tells him the men are pirates and they're after Sheeta. Pazu's boss turns out to be standing outside his own front door. As the pirates approach and threaten the boss, Sheeta, then Pazu are pulled inside and told by the boss's wife to run out the back door.
Meanwhile at the front door, Shalulu, the beefiest pirate, tries to intimidate the boss by flexing his muscles and bursting out of his shirt. A crowd gathers, and the boss, who's pretty beefy himself, bursts his own buttons. His wife looks over his shoulder, frying pan at the ready, and remarks that she's not going to mend his now-shredded shirt. The two men fight. Soon the villagers in the street take exception to the other pirates' heckling and the fight become a melee.
The car pulls up to the edge of a cliff, from which Dola and a couple more pirates can see the village street. "Leave it to my little idiots to start a riot," she says. Then she spots Sheeta and Pazu running toward the railroad tracks. The kids jump on a moving train, tell the engineer (voice: Matt K. Miller) the Dola gang is after Sheeta, and ask to be dropped off at the police station in the next town. The engineer, who knows Pazu, asks no questions; all he says is "help me stoke up the engine."
Dola drives through the village to extract Shalulu and his party of pugilists, who are astonished to hear that Sheeta has escaped. The villagers chase the car and throw things as it drives off; Dola throws them a hand grenade "to remember us by."
The engineer spots the pirates' car approaching the moving train; he says the engine is old and can't go any faster. Dola drives the car onto the tracks and draws closer to the train in a hair-raising chase over rickety trestles. When they catch up, Pazu releases the empty cars behind the engine and the train pulls away, but the pirates' car is moving so fast it pushes the loose cars ahead of it and they quickly catch up with the laboring engine. Pazu cranks up the brakes on the lead car and it slows down, separating the pirates from the engine before they can grab Sheeta. As Pazu waves good-bye from the engine, Dola, sounding like the Wicked Witch of the West, says "you'll get yours!"
The pirates heave a train car off the tracks, but pause as they're trying to jettison the second one because Dola notices a military spy plane, which she thinks is Muska.
Meanwhile, the engineer stops because there's an army engine coming toward him. He cheerfully says "it's the army to the rescue!" and asks for help for the kids, but Sheeta quickly realizes that the men coming from the military engine look just like the ones who were working with Muska. She says "good-bye, Pazu," and takes off, bad guys in pursuit. Pazu trips them before running after Sheeta. The quick-witted engineer scalds the bad guys with his steam-powered brakes when they try to shoot the fleeing kids.
The kids almost immediately see the Dola gang coming at them; they're still on a trestle, but Sheeta runs down a siding, telling Pazu not to follow her or he'll get hurt. The Dola gang catches up to them, destroying the trestle as they approach. Pazu and Sheeta jump off and dangle precariously as the gang's train car passes over them. Dola watches Sheeta and Pazu fall toward the town below and then, with a flash of light, they float back up as Sheeta's crystal saves them.
Pazu tells Sheeta, "this is what happened the first time I saw you—I knew there was something special about that necklace." Dola isn't surprised and tells her sons, "it's the power of the crystal." The soldiers from the armored train can see the kids too. They float gently down into a mineshaft.
The pirates go after them, while overhead, the spy plane watches.
Lost in the Mine
Sheeta's crystal, which has been glowing, goes dark when they land at the bottom of the shaft, but Pazu has a lantern. They walk for a bit in the old mine, then sit down to eat. (Pazu is still carrying the fried egg on toast he made for breakfast.) Asked where she's from, Sheeta says "I come from Gondoa, deep in the northern mountains." After her parents died, she cared for their farm animals until some men came and took her away—the same men in dark glasses who are now pursuing her.
Pazu realizes that the men and Dola are both after the crystal, which Sheeta didn't realize was so powerful. She says her mother gave it to her before she died, and told her never to show it or give it away to anyone. Pazu says "we orphans should stick together." Sheeta apologizes for getting him mixed up in her problems, but Pazu isn't sorry at all: "this is the most exciting thing that's ever happened to me!"
The children are frightened when they hear someone approaching, but it's an old miner friend of Pazu's, Uncle Pom (voice: Richard Dysart). They tell him there are pirates chasing them and the army is right behind the pirates, and Uncle Pom thinks that sounds splendid. He takes them to his camp by an underground lake and gives them tea. He says that the rocks speak to him, and they've been restless since last night. Then he blows out the lamp, leaving them in the silent darkness.
It doesn't stay dark long. Soon crystals on the floor, ceiling, and walls around them start to glow. Pazu wonders what's doing that, and Uncle Pom cracks open a rock to show him; it briefly glows. He says "it's a long-forgotten element called aetherium. People no longer know how to mine aetherium." Sheeta pulls out her crystal, which is glowing. The old man says "that's a pure aetherium crystal!" Pom tells them such crystals haven't existed since his great-grandfather's time; according to legend, only the people of the floating city of Laputa knew how to make them. It's aetherium that makes Laputa float. After a few minutes Uncle Pom is overcome and asks Sheeta to put the crystal away—"it's speaking too loudly to me, too sadly."
Uncle Pom's great-grandfather told him that the rocks become restless when Laputa appears over the mine. He tells Sheeta that the crystal's power comes from the earth, and to use it selfishly will bring great unhappiness.
Outside, the military spy plane flies off and the disheveled pirates, who are peeking out of the mine, ask Dola if they can go back to the ship. She says it's too quiet; they decide to sit tight.
The kids say goodbye to Uncle Pom at another entrance to the mine.
Once outdoors, Pazu and Sheeta climb a steep hill and stop to admire a huge cloud. Pazu is sure the cloud is hiding Laputa. Sheeta says she hasn't told him the traditional name her family gave her: Lusheeta Toel Ul Laputa. While they're talking, a plane spots them and lands nearby; they're captured by army men in green uniforms and a man in a dark suit and dark glasses, who knocks Pazu out with the butt of his pistol. Muska disembarks from the plane and growls "and about time!" when told they've been captured.
Pazu comes to in a bare cell in a coastal fortress. He hears soldiers drilling outside his arrow-slit window, but can't see them.
In a room above, Muska tells a portly general (voice: 吉姆·卡明斯) that they'll get what they want, but it will take time. The general responds that they're wasting time; Muska should twist an arm or two and the girl will talk. Muska says military tactics risk wasting more time. The general says military tactics would have saved them from Dola's interference, but Muska replies, "it was a military transmission that the pirates decoded." He says the general's job is to mobilize the troops when the time comes. The general says he's in charge of finding Laputa; Muska counters that as the government's secret agent, he's in charge of the general.
Sheeta huddles on a window seat in a sunny tower room. Muska walks in and picks up a dress, remarking that it's fit for a princess. Sheeta asks if Pazu's all right and asks to see him. "Your friend is being treated as if he were the guest of royalty," he says.
He takes her down in an elevator to show her a battered, broken giant robot. "Laputa was just a legend until this dropped from the sky." Muska explains that his job is to figure out the robot's—Laputa's—secrets. He points out a small red shield on the robot's chest; it bears the same symbol as Sheeta's crystal. He needs her help to get the crystal to lead them to Laputa. Sheeta tells him to keep the crystal and take Laputa's treasures for himself. Muska, trying to convince her that it's not about the money, says Laputa used to dominate the world, and it's still dangerous. And the stone only works for her. Sheeta just wants to see Pazu. Muska says if she'll cooperate, she can help free Pazu. If she won't, he can't control what the military might do to him. Then Muska calls her by her real name, Lusheeta Toel Ul Laputa. "Toel means ruler in Laputian; Ul means true. You are the legitimate heir to the throne of Laputa, Princess Lusheeta." Sheeta is stunned.
A Broken Promise
Pazu, meanwhile, is climbing the walls of his cell when a soldier comes to let him out to see Sheeta and Muska. Muska says there's been a misunderstanding; they had no idea how bravely he fought to defend Sheeta from the pirates. Pazu is confused, and still more confused when Sheeta tells him to forget about Laputa. Muska says Sheeta has agreed to help the army search (secretly) for Laputa, and Pazu really should forget about it. Pazu objects, but Sheeta leaves. Muska gives Pazu several gold coins "to show our appreciation of your efforts." Pazu walks out of the fortress. As Sheeta watches him go from her window, Muska fastens the crystal around her neck and tells her to remember the words that bring the crystal to life. "Keep your promise and you too will be free."
In the mining village, it's evening. A small child with a broom chases a pig out of her house. She see Pazu walking slowly up the street and calls her mother, the boss's wife, who comes out to say they've all been worried, and where has he been and what happened to his friend? Pazu only says "it's over now," and runs off. He comes to his own front door and finds the pirates making themselves at home. They discover the gold in his pocket and accuse him of selling Sheeta out; he replies that he only left because Sheeta told him to. "So you believed her and you came back here?" sneers Dola. Dola suggests that the army forced Sheeta to make a deal to save Pazu's life, and they're not likely to keep Sheeta alive once they get what they want.
A telegraph receiver on the table comes to life. Dola translates the Morse code: "They're calling for air destroyer Goliath. They're about to take off with Sheeta. We've got to hurry or it will be too late!"
Pazu begs to come with them. Dola agrees, thinking he'll be useful in getting Sheeta to cooperate. He grabs his father's aviator headgear, complete with goggles, and opens the dovecote so his birds can get out and feed themselves while he's gone. The pirates take off in their flapters, Pazu riding with Dola.
The huge airship Goliath arrives at the fortress as Muska and the general watch. The general asks if the girl has surrendered the information yet; Muska says it will take a little more time. The general says they'll have plenty of time aboard Goliath, and they'll depart at first light.
The pirates buzz through the night in their flapters. Dola urges them to hurry as they have to get there before sun-up. Pazu thinks of Sheeta.
Sheeta's looking out at the night and remembering a time when her grandmother taught her a spell that would help her if she was ever in trouble. Sheeta learned the words in Laputian; in English, they mean "Save me and revive the eternal light." She recites the Laputian, and her crystal lights up and emits so much energy that she cries out in distress and tries to cover her eyes. Far below, the robot is activated and its broken parts move together. Muska comes into her room, saying "the sacred light! The ancient documents were true—it's not just a legend!"
He reaches for the glowing crystal but it seems to hurt him. He pulls his hand back but demands that she tell him the spell. The soldiers guarding the robot think they hear something and open its door, which it blocks when they try to close it again. They get on the phone to say the robot is alive. It bursts out of its prison; at the same moment, the crystal goes dark. When Sheeta and Muska come out of her room, they see the robot climbing the stairs toward them. The soldiers shoot at it, doing no damage, then shut the fire door at the top of the stairs. The robot melts it. Muska is amazed at the robot's power. He realizes the crystal has brought it to life. The robot uses a laser to cut the wooden walkway where Muska, Sheeta, and others are standing; the pieces separate, leaving Sheeta alone on one side. The robot unfurls its wings, flies up the inside of the tower, and follows the terrified Sheeta up the stairs at the top. On the roof of the tower, her crystal flashes again and points through the clouds—at Laputa, she and Muska both believe, but we can't see it. The robot breaks through the roof of the tower as the soldiers bring their artillery to bear on it. The robot communes with the crystal for a moment before it's hit by a shell and falls. The soldiers try to revive Sheeta, who groans, and then the robot comes back to life. It picks her up and starts shooting with its laser eye. It does a lot of damage to the fortress, leaving much of it in flames, and starts setting fire to the surrounding countryside.
From their flapters, the pirates see the fortress lit up in the distance. The sun is beginning to rise. When Sheeta comes to, she tells the robot to stop, climbing up to sit on its shoulder. But by then everything around them is burning.
Pazu has spotted them, though, and directs Dola to the top of the tower. In trying to get close enough to grab her, they clip the tower; Dola is knocked out and the flapter plummets toward the water below until, at the last moment, Pazu gets to the controls and pulls out of the dive. Dola recovers and they make another attempt to get Sheeta. The robot, which seems to be in some kind of trouble itself—burning out from within—has put Sheeta on the battlements of the tower. Muska sees what they're up to just as Pazu, hanging upside-down from the flapter, grabs Sheeta. "It's not over," Muska promises himself as the pirates fly off.
An Adventurous Trip
As the general expresses his anger over the loss of Sheeta and the robot and orders a pursuit, one of Muska's men draws Muska away: "I think we may have found what you've been looking for." Muska finds Sheeta's crystal on the ground near the tower, still pointing to Laputa. He's able to pick it up. He sends a message to the general that they'll be departing on time.
Sheeta cries on Pazu's shoulder as the pirates fly them toward Pazu's home. Dola is annoyed because Sheeta lost the crystal. Pazu asks if they can sail with the pirates. They say they'll work, and Sheeta says she needs to find out about Laputa for herself. They fly over Pazu's house but keep going and rejoin the pirates' airship, the Tiger Moth. One of Dolas sons takes Pazu to the engine room and introduces Pazu to his father, a short bald man with a huge mustache. He's the ship's engineer, and he needs an assistant. Pazu immediately shows his mechanical ability. After conferring with Sheeta about the location of Laputa, Dola announces that Goliath is heading for Laputa and they're going after her. The first to spot Laputa will get 10 gold coins.
Dola takes Sheeta in hand, telling her she has to start talking like a pirate (Sheeta's "shiver me timbers" is not convincing) and dressing like a pirate (Dola gives her an enormous pair of pink pants). And Sheeta has to clean up the filthy galley (which is piled high with dirty dishes, pots, and pans) so she can start producing the five meals a day the hungry pirates require. Dola gives her an hour. When Dola opens the galley door, most of her sons fall into the room—they've been outside listening.
Later, as Pazu hangs on the hull of the airship hammering at something, one of Dola's sons peers through the galley porthole at Sheeta, who's making soup. He goes in and offers to help. It turns out that several of his brothers are already there with the same idea.
In the captain's quarters, Dola and her husband are playing chess. He remarks that its not usual for her to challenge a ship like Goliath. He says the kids are cute, and the little girl reminds him of Dola. Cut to the crew, eating hungrily and asking Sheeta for seconds.
That night, one of the sons comes to wake Pazu, who's sleeping on the floor under some bunks; its Pazu's turn to stand watch. The pirate gives Pazu a brown poncho, remarking that it's cold, and sends him up the ladder on the outside of the ship to the crow's nest at the top of the hull. Sheeta, who's been sleeping on Dola's floor, gets up and follows him. She's almost blown away as she climbs into the crow's nest. They talk a bit and Pazu throws the poncho over her, so they're both in it at once. Dola is awake and can hear them through a speaking tube. Sheeta confesses that she's afraid of going to Laputa; she doesn't want anyone else to get hurt. She feels awful about the robot, which died to save her. As Dola listens, Sheeta talks about the spells her grandmother taught her—not just the one that revived the robot, but a spell to find things, a spell to cure sickness, and a spell of destruction, which her grandmother told her never to use. (To give power to good spells, she had to know evil ones too.) But she never knew the spells were connected to her necklace. She worries that Laputa has the same power as the necklace, and poses the same danger if the power is misused.
Pazu argues that even if she'd thrown the crystal away and they'd never met, sooner or later someone would have managed to land on Laputa and claim it. They can't let it fall into the hands of people like Muska. If they run away, Muska will chase them forever. Sheeta feels bad that Pazu is becoming a pirate; he says he isn't going to become a pirate, and Dola will understand—"she's much nicer than she pretends to be." He promises that after they find Laputa, they'll go to Gondoa and see her old home. Then they spot Goliath, a shadow in the clouds beneath them, and raise the alarm.
Dola orders a change of course, but Goliath breaks through the clouds and starts shooting at them. Tiger Moth quickly descends into the cloud layer; they get away without much damage, and Goliath doesn't pursue.
On Goliath's bridge, the general argues for chasing the Tiger Moth. Colonel Muska won't let him, saying it's a waste of energy. He has Sheeta's crystal on the compass, still directing him to Laputa.
On Tiger Moth's bridge, Dola calls up to Pazu through the speaking tube. She says they can't lose Goliath, so Pazu must keep her in sight. To do that, he'll have to release the crow's nest from its moorings on the hull; it remains attached by a cable and flies like a kite. She explains how to release it and open the wings, then tells Sheeta to come down because flying the kite is man's work. Sheeta points out that Dola is female, and that she, Sheeta, grew up in the mountains, and she can handle this. Dola, laughing, gives in and says once they take off they'll need to use the phone to communicate. Dola's phone immediately rings; when she picks it up, Sheeta's voice says "you mean this phone?"
Pazu releases the kite. The ride is peaceful except when the wind gusts. They can't see Goliath, but Pazu does see a storm coming. As a precaution against the storm, Pazu tells Sheeta to get rope out of his bag and tie them together. On the bridge, the pirates note that the mercury is dropping fast and it's an hour to sunrise. When the sun comes up, Pazu and Sheeta notice that it's in the wrong place—or more accurately, they're flying in the wrong direction: east, not north. The bridge reports that something is confusing the compass, which is pointing east. Sheeta sees the cloud that covers Laputa, heading right for them. Dola, realizing it's also a hurricane, orders the engines to reverse, but the Tiger Moth is already caught in the winds. When Goliath appears above them, they're sitting ducks.
Pazu and Sheeta in the kite and Muska aboard Goliath are determined to get through the storm to Laputa. The kite passes through an electrical field into a weird zone where for a moment Pazu catches site of a familiar ghostly airship, and recognizes the pilot—his father. Then they break into relatively clear air over Laputa. They're still trailing their cable, but its not attached to the Tiger Moth any more. It drags among the vegetation on Laputa, slowing them down so they come to a softer landing than they might otherwise have done, but it's not gentle. Pazu and Sheeta are knocked out when they land and fall out of the kite.
The Wonder of a New Place
As they lie there, the fog and clouds disperse. They come to on a sunny, flowery lawn at the top of a tower, still tied together. Thrilled at finally being on Laputa, they laugh and hug each other and twirl exuberantly. They can see old stone structures that look a little the worse for wear, and a huge tree that seems to be the center of the island. A giant robot shows up and picks up their kite. Sheeta thinks it can't know who she is as she doesn't have the aetherium crystal, but she asks it not to take the kite as they need it to get home. The robot pauses and seems to register her remarks, but moves the kite anyway. There's a bird's nest underneath it, holding three eggs. The robot puts the kite down nearby and flashes and burbles at them, which Sheeta understands to mean they should follow. The robot leads them across a bridge, where they see some small animals dive into an ornamental pool. But when they peer into the water, they can see a city down there. The robot is still walking. They run to catch up; it leads them to an enormous garden. The garden is enclosed in nearly invisible walls; at the center is a giant tree that Pazu guesses is a thousand years old. There's some stonework scattered around, and some inside the tree. They see another robot and realize it's not the one they followed; this one is dead and seems to have been frozen in place for a very long time. Looking more closely at the roots of the tree, then can see that they're littered with dead, moss-covered robots.
On a flat stone that looks like a grave marker, someone has laid a row of pink flowers. Their robot comes back holding another pink flower, which Sheeta takes with thanks. Some striped animals that look like a cross between cats and squirrels appear on the robot's shoulders and chase each other around its neck. The robot looks at them and goes about its business. The kids think it's probably the only working robot left.
In the underground part of the city, a detonator triggers an explosion. It disturbs birds and is followed by several smaller explosions—or aftershocks. Pazu and Sheeta run off to find the source of the disturbance. They find a section of the city that's been destroyed—Pazu attributes that to the army.
Sheeta and Pazu spot Goliath, moored at the edge of a large plaza and disgorging crowds of soldiers from two gangplanks. Beside it are the ruins of the Tiger Moth. Sheeta worries about Dola and the boys; Pazu sees that they've been captured. They know the pirates will be hanged if they can't help them escape.
A soldier brings the general a heavy, jeweled necklace; he reports they've broken through the wall and the city is full of treasure. The general taunts the pirates with the necklace and tells Muska to send a radio message about their discovery of the city, adding snidely, "see if you can make it difficult to decode." He runs off to keep his underlings from pocketing any jewels, and Muska smugly observes that the jewels have thrown "those fools off the scent."
Pazu has a plan. He and Sheeta climb down the roots of the giant tree toward Goliath. They peer through a high window into a huge chamber where soldiers are rushing to and fro, grabbing treasure and taking it outside. But there's shooting going on as the looters work. Some other soldiers break through a door, enter the chamber, and fight with the looters. Sheeta says they can't let the soldiers ruin the garden too. Pazu says they have to find the aetherium crystal to protect the garden, then notes that all the storm clouds around Laputa have disappeared. If that hadn't happened, the army wouldn't have been able to land. Pazu thinks they used Sheeta's crystal to dispel the storm, and resolves to prevent Muska from learning to use the crystal. Sheeta realizes that the spell of destruction might be the only way to do that. Just then they hear soldiers nearby, looking for them. They sneak off among the tree-roots.
The kids climb down near the Tiger Moth, staying out of sight as much as they can. At the broken foot of an arcade below the plaza where the ruined Tiger Moth and her crew are being held, Pazu has to jump from one pier to the next. But the pier he jumps to crumbles as he climbs. While he struggles to hang on, Muska and two of his men emerge on the walkway Sheeta and Pazu were on a minute before; they're looking for a door. Sheeta is just a few yards away hiding in a niche, and Pazu is in full view behind the men, trying to reach a window. Muska, consulting a little blue book, finds the hidden door and uses Sheeta's crystal to open it. They turn around when they hear Pazu knocking loose another chunk of masonry and one of Muska's henchmen takes a shot at him as he reaches the window. Sheeta rushes them, knocks one over, and tries to run, but Muska catches her by a pigtail. Pazu, too far away to help, shouts at them not to hurt Sheeta. The henchmen shoot again and a bullet grazes Pazu's cheek; he disappears inside as the soldiers on the plaza above him look down. Muska tells them he's caught another pirate, and there's one more under their feet. Pazu shouts to Sheeta that he'll find her. Muska and his party go through the secret door with Sheeta in tow; the opening disappears behind them.
The soldiers above Pazu throw a hand grenade through his window; when it goes off, the smoke comes up through the paving stones the pirates are sitting on. Dola pushes a brick down into the hollow space below her. When the soldiers run off, Pazu looks up through the hole. He says he's going to rescue Sheeta, but first he cuts Dola's ropes first and passes her his knife. In return, Dola shakes a large, wide-mouthed handgun and a couple of shells out of her pant leg, so Pazu is armed. In the treasure chamber, the general's men report that Muska destroyed all the radios, and that Muska and his two men were seen heading for the black dome (an inverted dome under the island that presumably houses the tech keeping it afloat). The general orders his men to arrest Colonel Muska. Pazu watches them march off.
Muska, Sheeta, and Muska's two henchmen descend into the black dome on an elevator platform. They pass through a shaft made of black stone blocks carved with geometric designs. When they reach the bottom, Muska leaves his protesting men behind, saying only royalty is allowed to enter the central chamber. He and Sheeta descend a little further and enter a chamber that's been infiltrated by tree roots. Muska is angry, saying the roots don't belong there and he'll have them burned. He checks his little blue book again and directs Sheeta down a corridor, also lined with tree roots. Muska pulls some roots aside to expose a door, which glows and opens when he holds the crystal against it. Inside is a bright sort of garden, walled with tree roots, lit by a glowing ball of tree roots at the center, and full of tall plants that reach Muska's shoulders. He's furious at finding more roots and plants here. He pushes through the roots surrounding the glow in the center and reveals a large, blue rotating octahedron. He exults that at last he's found the largest aetherium crystal ever—Laputa's power source.
Muska says the stone has been awaiting the return of its king for 700 years. Looking at his book again, he wades through the plants and finds a slant-topped black stone like a podium, with writing on the slanted surface. Batting aside a cloud of gnats, Muska checks the black stone's inscription against his book and says they're the same. Sheeta asks him who he is, and he says he, too, has an old, secret name: Romska Polo Ul Laputa. He says he and Sheeta share royal ancestors, but their ancestors left Laputa to live on Earth, which Muska considers a mistake.
As Pazu clings to a tree root on the outer surface of the black dome, there's an explosion. The soldiers who set off the explosion run to the site of the blast—they seem to be trying to open Muska's hidden door—and find that the stone is singed but undamaged. The general is ordering them to try again using all the dynamite they have when Muska's voice over a PA system says there's no need to do that; they may come in. Muska moves Sheeta's crystal over the surface of the black podium stone. Some symbols light up and the big carved black blocks in the central shaft move out of the walls of their own accord and rearrange themselves. Muska's two men, who have been trying to climb out, are knocked loose. They scream and fall. The black dome rumbles and shakes, then starts to open. The vine Pazu is clinging to breaks loose at the top and he falls with it, hollering. It swings and he's able to grab another vine that's still attached. A panel opens above him and a huge stone column that looks like a jet emerges; we can see that there are seven of them arranged in a circle near the bottom of the black dome. Pazu scrambles away.
The general and his soldiers are invited to walk through a door Muska has caused to open for them. They still can't see him. A room like a viewing platform opens at the bottom of the dome and the general and the soldiers go in. Pazu can see what's happening from the outside. Muska projects images of himself and Sheeta into the room and announces to the soldiers that they're in the presence of the king of Laputa. He demonstrates the power of the reborn kingdom of Laputa by creating a sort of bomb with the seven giant jets and dropping it through the clouds. They can't see where it falls, but they see the top of its fiery mushroom cloud. "The fire of heaven that destroyed Sodom and Gomorrah in the Old Testament!" gloats Muska. "The Rhamaniya referred to it as Indra's Arrow. The entire world will once again kneel before the power of Laputa!"
The general changes his tone: "Well done, Muska! You're a credit to our country. As such, you deserve this reward!"
He shoots at the projection of Muska, which has no effect except to make Muska sneer at his stupidity. Muska reaches for the black stone; Sheeta bites his hand and tells them to run. Some do, but the general and many soldiers are still standing there when the floor is pulled out from under them. As they fall, Muska laughs and his projection disappears into the ceiling.
Surviving soldiers run through corridors in the dome. They pass giant robots coming to life and emerging on all fours from niches in the walls. When the robots get outside, the pirates spot them and decide to run for it in their flapters, which are undamaged inside the wreck of the Tiger Moth. The soldiers are rushing back aboard Goliath, but it pulls away before everyone has boarded, sending those on the gangplanks to their deaths.
Once her crew is aboard the flapters, Dola is reluctant to leave without Pazu and Sheeta. In the aetherium crystal's garden chamber, Muska throws Sheeta to the ground and tells her she'd better be gracious to the new king, as she'll be spending a lot of time with him. He uses the black podium to call up an image of Goliath, which is shooting at Laputa. He scoffs that the fools don't understand that it's useless to fight him.
Goliath's artillery knocks Pazu from his vine on the underside of the dome. He gets a toehold at the lip of a chute that disgorges a stream of flying robots, which attack Goliath. Once the robots are away, Pazu takes off his shoes and climbs up the chute. At the top of the chute he finds a space filled with gears and other mechanisms; he keeps climbing and shouts for Sheeta.
Outside, the robots are destroying Goliath; Muska watches and gloats while Sheeta tells him to leave Goliath alone. She gets loose (her hands have been tied since Muska caught her at the secret door) and rushes Muska, demanding her crystal. She grabs it and runs. She pounds on the door of the garden chamber while Muska strolls over, telling her to be good and give the crystal back. The door disappears before he reaches her—her crystal lights up—and she runs again. Muska, still unconcerned and unhurried, continues to follow her. He tells her that no one can hear her, and only he can help her.
Pazu uses Dola's gun to make a hole in a wall. He scrambles through and runs, still shouting for Sheeta. Finally Sheeta hears him and runs toward his voice. Just before Muska catches up, Sheeta passes her crystal to Pazu through a tiny opening; she tells Pazu to throw it in the ocean. Muska has a revolver. He tries to shoot Pazu through the chink, then warns him to protect the crystal if he wants to see the girl alive. Pazu blasts a bigger hole in the wall, crawls through, and runs after them.
Sheeta runs into an empty room; Muska follows and shoots. She drops and he tells her to get up, which she does. "How appropriate that we've ended up in the throne room," he remarks.
Facing him across the floor, Sheeta answers that it's no longer a throne room—now it's their tomb. A king without compassion does not deserve a kingdom, she tells him. She recites the words to a song from her home valley of Gondoa: "Take root in the ground, live in harmony with the wind, plant your seeds in the winter, and rejoice with the birds in the coming of spring." No matter how many weapons you have, the world cannot live without love. He aims at her again and shoots off one of her pigtails; she barely flinches. He insists that he'll return Laputa to life, that its power is the dream of all mankind. He shoots off her other pigtail and says "your ears are next unless you get on your knees and obey me. Give me that stone!"
Pazu arrives and tells Muska he's hidden the stone. Muska says he'll kill Sheeta if Pazu doesn't produce the stone. Pazu responds that Muska can have the stone if Pazu can talk to Sheeta. Throughout this exchange, Sheeta implores Pazu to take the stone and run. Muska gives them a minute to decide what to do. Pazu embraces Sheeta and asks her to whisper the spell of destruction in his ear so they can say it together. "Put your hand in mine and trust me," he says, showing her the crystal in his hand. He tells her Dola and the boys are free, so she doesn't need to worry about them. When Muska says their time is up, Pazu throws down his gun. They hold out their clasped hands and say a single word, "Balus."
The big crystal flashes, as does the small one in their hands, dazzling them and Muska, who screams. The big crystal falls, breaking through its enclosure, and Laputa begins to disintegrate. Muska, blinded, stumbles around screaming "no!" The pirates finally shove off in their flapters but hover nearby to watch Laputa fall apart. Under the island, it rains masonry and broken robots. Dola realizes Sheeta and Pazu used the spell of destruction to save Laputa from Muska.
One of the pirates sees a blue light among the roots of Laputa's central tree. The spell doesn't seem to affect the central tree and the structure most closely attached to it (the garden?)—or the giant aetherium crystal. Once it has shed the black dome and most of the buildings, the tree floats off, the pale blue crystal glowing through its roots.
Sheeta wakes up among the roots of the tree with Pazu. Sheeta says they survived because they protected the tree, and it protected them in return. They find their kite, which looks intact. They climb aboard and take a last flight around Laputa. They see the last robot still tending the garden.
When they leave Laputa behind, the kids soon encounter the convoy of pirates in their overloaded flapters. The pirates are overjoyed to see them alive. Dola's husband, the Tiger Moth's engineer, mourns the loss of their airship, and Dola, calling him a big baby, promises to buy him another one. Which it turns out they can easily afford—every pirate shows off jewelry worth a fortune. Pazu and Sheeta don't stay with the pirates, though; they get back in the kite and fly off into the clouds together. Perhaps they're heading north, for Gondoa.