After being at home for only ten days, Gulliver is visited by a ship captain who invites him on a voyage departing in two months. Gulliver convinces his wife that this is a good opportunity and sets off, again working as the surgeon. After they sail for three days, a storm arises, driving the ship to the north-northeast, where they are attacked by pirates. They are unable to defend themselves. Gulliver insults the captain of the pirate ship and as punishment is set adrift in a small canoe, with paddles and a sail, and four days provisions.” On the fifth day of sailing in his canoe, Gulliver reaches a small island, where he spends the night in restless sleep. In the morning he notices that what he thought was a cloud floating above the island is actually a floating island. Gulliver calls up to the people he sees moving about the island. They lower down a system of pulleys that can pull Gulliver up.
As soon as Gulliver steps onto the floating island, he is surrounded by a crowd of people. He finds them very strange even though they are of a size similar to his. Their heads are slanted to the left or right, and their clothes have pictures of either musical instruments or astronomical signs. Gulliver learns that he is on Laputa. The people here have terribly short attention spans, so they carry around “flappers.” These are used for hitting other people during conversation in order to keep them focused. After dinner a man is sent to teach Gulliver the language. Gulliver finds that the Laputian houses are built very poorly and with no right angles. This is odd because the men here are obsessed with mathematics. The people here never have peace of mind. They are constantly worrying about dangers such as the possibility that the sun might go out. The women are very sexual creatures who often cheat on their husbands, especially with their preferred men from Balnibarbi, but the men are so wrapped up in mathematics that they do not notice. The king of Laputa is not remotely interested in the government of England.
Gulliver learns that Laputa is floating above Balnibarbi, the island on which he landed his canoe. Laputa contains 10,000 acres and is perfectly circular. It is able to move about the surface of Balnibarbi but not beyond its borders, and it can move up and down because of its magnetic forces. When a town from Balnibarbi acts up, the King has Laputa moved directly above it so that it can receive no sun or rain. No one from the Royal family is allowed to leave Laputa.
Gulliver finds Laputa terribly boring because the people there are all much more intelligent than he is. He has a hard time conversing with them and is generally ignored. He petitions to go down to Balnibarbi, and his request is granted. On Balnibarbi, Gulliver meets Lord Munodi, who invites Gulliver to stay at his home. Munodi’s home is beautiful and kept well, but when the two travel out into the country Gulliver finds that the rest of the land is barren and sadly kept. Munodi explains that this is because many years back, people from Balnibarbi visited Laputa, and when they returned they decided to change things to a more academic way of living. This idea has failed. Munodi’s land is plentiful because he never changed his way of living.
Gulliver visits the Grand Academy of Lagado, the largest metropolis of Balnibarbi. The scientists there are constantly working on experiments that Gulliver finds pointless. For instance, he meets a man who is trying to extract sunlight from cucumbers. Other experiments are trying to turn excrement back into the food it began as, trying to make gunpowder from ice, and trying to employ spiders as weavers of silk. Professors are also attempting to alter the communication of Balnibarbi by doing away with language altogether.
Gulliver then visits the part of the Academy designated for studies of government. He finds the professors especially in this wing to be entirely crazy. They propose such things as studying excrement to find treasonous people and taxing people based on beauty and wit.
Gulliver decides to take a trip to the Island of Luggnagg but finds that no ships will be available for the voyage for a month, so it is suggested that he visit Glubbdubdrib, which he translates to mean the island of sorcerers or magicians. Once he arrives in the governor’s home, he finds that the governor and his family are served and attended by domesticks of a kind somewhat unusual. Gulliver learns that the governor has the power to bring back the dead for the purpose of serving him. Gulliver is given the option to bring back anyone he would like. He chooses Alexander the Great, who tells Gulliver that he actually died because he drank too much. He then brings back a parade of other famous dead.
Gulliver spends a great deal of time speaking with various famous dead people. He speaks with Homer, Aristotle, and Descartes and even gets them into conversation with one another. He later brings back a few English Yeomen and finds them much larger and stronger than the English people today. He worries that his countrymen are diminishing with time.
Gulliver travels to Luggnagg, posing as a Dutchman. He says, “I thought it necessary to disguise my Country, and call my self an Hollander, because my Intentions were for Japan, and I knew the Dutch were the only Europeans permitted to enter into that Kingdom.” His true identity is discovered, however, and Gulliver is made a prisoner. He later learns that anyone who wants to come before the king must crawl on hands and knees and lick the floor. The king, it turns out, uses this tradition to his advantage when he wants to get rid of someone-simply by poisoning the floor.
Gulliver learns about the Struldbrug children who are born to Luggnaggians but who have a red dot on each of their foreheads. These children are immortal, which causes Gulliver to fantasize about what he would do if he were immortal. He dreams of the ability to take his time becoming a master of many different subjects and amassing great wealth. But Gulliver soon comes to learn that the Struldbrug children are actually very unhappy and jealous of those people who can die. They find their own lives depressing.
After offering Gulliver employment in the court but finally seeing that he is determined to leave, His Majesty gives him license to leave, a letter of recommendation to the Emperor of Japan, and a gift of 444 pieces of gold and a very valuable red diamond. In Japan he is told to trample the crucifix, which all Dutchmen are happy to do, but Gulliver manages to get out of doing so. He takes a ship to Amsterdam and then to England, where he happily returns to his family.