J., the narrator, is sitting around a fire with his two friends, Harris and George, as they compare their various illnesses. J. recently spent some time researching diseases at the British Museum and concluded he had them all except for “housemaid’s knee.” Though none of the men actually appear ill, they agree that whatever they’re suffering from must be caused by “overworking.” They decide the best course of action is to take a trip away, and after some deliberation agree to boat up the river Thames.
Though the men conceive of the trip as a return to nature, in which they can spend time embracing a simpler and purer life, packing turns out to be a complicated and drawn-out affair. They keep forgetting things they need and have to start over. While they do so, J. tells the reader that Harris reminds him of his Uncle Podger, who always makes a simple task overly complicated. J. also implores the reader to get rid of their superficiality and materialism—to throw away the “lumber” that so burdens people as they travel on the “river of life.” The men then discuss what food to take with them, which reminds J. of the time he transported cheeses from Liverpool to London as a favor for a friend. Wherever he went, people recoiled from the strong smell of the cheeses and in the end even his friend didn’t want them.
Once the men finish packing, it’s clear they haven’t followed J.’s advice too closely, given the sheer number of bags they have crammed with clothes, luxury food, and kitchenware. It’s also getting late, so the men go to bed, with George promising to rise early and wake the others.
The next morning arrives, and the men have overslept. J.’s housekeeper, Mrs. Poppet, had assumed they wanted to have a lie-in. As they sit down to breakfast George reads the forecast from the newspaper. Even as J. complains about the inaccuracy of such forecasts and barometers, it is currently sunny outside and the men believe they will be blessed with good weather for their trip. George heads off to his job at the bank and plans to meet the others later, so J., Harris, and the dog Montmorency go to London’s Waterloo station in order to get the train to Kingston, where they will pick up their boat. At Waterloo, however, nobody seems to know where the trains are going, so the two men end up bribing a train driver to take them to Kingston.
Upon picking up their boat from this historic town, J.’s imagination runs wild as he pictures Kingston in its glory days. Centuries prior, Kingston was a place where kings were crowned and “nobles and courtiers” roamed the streets. J. praises the quality of construction back then and mentions one magnificent oak-walled shop that has since been covered with garish blue wallpaper. J. philosophizes about the nature of art and the way it’s valued by society. It seems to him that the fashionable objects of his day—which tend to date from one or two centuries earlier—are only valued because they’re old. Perhaps, he thinks, contemporary “commonplace” items will also come to be treasured relics in a hundred years.
J., Harris, and the dog float past Hampton Court, a majestic palace formerly occupied by Henry VIII. Harris once got lost in the maze there and needed rescuing by the maze-keeper. At Molesey, they go through their first lock—a mechanical system that controls the water flow of the Thames. Molesey is one of the most pleasant parts of the river and is popular with picnic-goers and boaters alike. Surveying the scene, J. discusses the fashion of the time, and says that girls frequently dress in clothes that may look great but are totally unsuited to the river environment.
The two men and the dog stop for some lunch at Kempton Park, where an angry man accuses them of trespassing on his boss’ property. J. and Harris just laugh him off. Harris then says he would burn down the houses of property owners and sing comedy songs on the ruins. This reminds J. of a party they once went to, at which he and the others in the crowd heard a song performed by Herr Slossen Boschen, an old German master. Before the performance, two German students at the party had told the crowd it was a comedy song. Not knowing any German but not wanting to appear ignorant, the audience laughed at what turned out to be a serious and tragic folk song.
Soon, the boat arrives at Weybridge, where George is waiting. He gets in carrying a strange-looking package that turns out to be a banjo, an instrument he’s never played before. The men take it turns to tow the boat by pulling it along with rope from the river bank. Girls are especially bad at towing, they men agree.
After a little while the group stops for dinner and sets up for the night. They’ve brought a canvas cover for the boat to sleep under, but have great difficult putting it up, tangling themselves up in it and falling over. Once it’s finally set up and they’ve had dinner, the men relax and seem genuinely at peace. They smoke their pipes and tell each other stories. As the day draws to a close, J. praises night-time’s ability to ease people’s pain and make them feel the presence of something “mightier” than themselves. As the other men drift to sleep, he invents a curious tale about three knights in a wood, one of whom gets injured and separated from the group. A vision appears to him—the reader is only told that this vision is called “Sorrow”—which leads him to the castle where he is reunited with the other knights who had thought him dead.
George wakes up early the next day and recounts a time when, because his watch was broken, he dressed himself and went to work without realizing it was still the middle of the night. George and J. wake up Harris, and the three agree that it’s a good morning for a swim. They prove too scared of the water’s coldness though, and chicken out. J. tries to trick the other two by wetting himself with a little bit of water, but accidentally falls in. For breakfast, Harris makes scrambled eggs, but burns the pan and ruins them.
The men and their dog arrive at Magna Carta island, so named because it is said to be the location where King John signed the Magna Carta, an important English document that enshrines certain ideas and standards about human rights. J. again imagines himself in the historical scene, when “King John has stepped upon the shore, and we wait in the breathless silence till a great shout cleaves the air and the great cornerstone in England’s temple of liberty has, now we know, been firmly laid.” Later, the men stop for lunch. Both J. and Harris get depressed because they haven’t got any mustard but are cheered when they remember that they’ve brought some tinned pineapple for desert. Unfortunately, they’ve forgotten the tin-opener, and after all three men struggle with the tin, they throw it into the Thames out of frustration. After lunch, the boat passes by Maidenhead, which J. says is “too snobby to be pleasant” and is home to many of the steam-launches on the river. The three men profess their hatred the steam-powered boats and say they often deliberately get in their way.
Next, they visit Marlow, which is home to the former house of Percy Bysshe Shelley. The men go to replenish their food stocks and once again acquire much more than they need, heading back to the boat with a trail of young shop-helpers carrying their goods for them. They get back on the river and reach Hambledon Lock. There, they ask the lockkeeper for some drinking water, and he tells them, in all seriousness, to drink from the river. The men once made tea with river water, but just as they had started to drink a dead dog floated by and put them off.
When the men stop for lunch, Harris falls into the river while slicing a pie. He accuses the others of pushing him in. After some more time on the river, the men settle down for the evening relatively early. Harris makes an Irish stew, a hodgepodge into which seemingly anything can go; Montmorency even offers up a dead rat. George and J. head into the nearby town, Henley, for some drinks. On returning, there doesn’t seem to be any sign of Harris. Eventually they find him in a daze from fighting a group of swans.
The men set off the next morning, arguing over who has been doing the most work on the trip. Each man accuses the other of shirking his duties. J. talks about the different methods for boat travel, such as rowing, punting, and sculling. George remembers seeing one punter lose the boat from beneath him, leaving him hanging onto the long punting pole for dear life. J. once tried to sail with a friend of his, Hector, but they messed up the raising of the sail, broke their oars, and had to be rescued. The three men head to Reading, passing by a house in which Charles I used to play bowls. It’s here that they encounter the most macabre moment of their trip: they spot the floating corpse of a young woman in the river. They learn that the woman had committed suicide after her family and friends disowned her following some kind of scandalous affair.
At Goring, the men try to wash their clothes in the river but only make them dirtier. They pay a washerlady in Streatley to do it for them. While in an inn at Streatley, they notice a huge trout hanging on the wall in a glass case. Locals come up to them intermittently and talk of how they were the ones to catch the great fish, but it turns out they’re all lying—the fish is a model. Continuing up the river, J. praises the beauty of the flower gardens kept at the locks they pass. He remembers them once being at a lock and nearly crashing the boat because a photographer was taking a picture of them and they were too focused on looking good.
They reach the final destination of the trip, Oxford, when rain starts to fall. For two days the men try and persevere with the weather but all the food grows damp, and when they try to sing songs to raise their spirits, the music seems to have a melancholy quality. Harris imagines what it would be like that evening back in London at their favorite theatre, and after some initial feigned resistance, the men decide to cut their trip short and head back. They assert it’s simply because it’s best for their health to get out of the rain. The 5:00 p.m. train takes them to London. They leave their boat behind, pretending to the boatman that they will return in the morning. Arriving in London, they feel instantly at home, enjoying some ballet at the Alhambra theatre before going for dinner at their favorite French restaurant. As they sip their wine and tuck into their steaks, Harris prepares a toast praising their alleged accomplishments: “we have had a pleasant trip, and my hearty thanks for it to old Father Thames—but I think we did well to chuck it when we did. Here’s to Three Men well out of a Boat!”