For Sal and Dean, Mexico is a "magic" land, full of cheap beer and cheap cigarettes. They are ecstatic at the world they have found, a world at "the end of the road." They drive through Mexico, excited at the prospect of getting to Mexico City and the adventures they will have while there. They pass through towns full of poor field workers, but the scene excites them. They feel they have found a true land of the "beat," people unencumbered by the trappings of money and work and white America.
They drive through many Mexican towns, taking turns at the wheel so that they can take in the sights and sounds of the people and the terrain of Mexico. They are fascinated by the way of life here and do not want to miss any of it. In Gregoria, a small Mexican town, they stop and meet Victor, a Mexican guy who says he can get them girls and marijuana. Victor's mother grows the drugs in her backyard, and Victor rolls the largest joint Sal has ever seen, a cigar-sized joint. They all smoke it on Victor's porch, immediately getting very high. They all get so high that they have trouble talking to each other.
Victor leads the group to the girls. Sal is so high that he begins having hallucinations in which Dean looks like Franklin Delano Roosevelt and God. He has visions of Mexico, hallucinations where he sees gold pour from the sky. Victor shows the group his baby son, and they all feel mournful desires for family and children-then they head for the whorehouse.
At the brothel, the three are treated like kings. The proprietor puts on Mambo music at their request, and they dance with the girls while the town watches through the windows. They drink and party with the girls, getting to know each one. Sal wants to have sex with a sixteen-year-old black girl, but he does not after he sees her mother come to talk to her. Stan has a fifteen-year-old Mexican girl. Sal eventually goes with another girl, not his first choice, who wants thirty pesos (about three and a half dollars) for sex. Sal does not care and throws money at her. A big crowd has begun to gather outside the whorehouse to watch the Americanos dance and party with the whores.
An eighteen-year-old Venezuelan girl, drunk, latches onto Sal and gets him to buy her drinks. Sal desires her but does not have the heart to take advantage of her while she is drunk. He decides he wants to take her to a room, undress her, and then talk with her. His desire conflicts with the domestic instincts he has been feeling throughout Part Four. Sal keeps watching the black girl he had wanted earlier. He watches her sweep the floors and realizes how poor she is and how much she needs money. He contemplates just giving her money, but he thinks she might look at him with scorn and that he could not handle that. Sal thinks that he might be in love with the fifteen-year-old girl. Victor frantically shows the group that they have run up a tab of over three hundred pesos-thirty-six dollars. Sal convinces Dean that they need to bring the day to a close and get back on the road. They finally leave, dragging Stan out of the whorehouse, although he wants to stay and try out some of the girls of the night shift. They leave Gregoria to the celebratory goodbyes of the whores and the rest of the town.
Outside of Gregoria, Dean discovers that the lights on his car have stopped working. They decide to drive through the jungle in the dark. After a few miles, the lights finally come on, and the group revels in the new jungle climate and scenery they have entered. At a small jungle town, they pull the car over to sleep. Sal climbs on the roof and feels that he has become a part of the jungle, feeling the humidity and the bugs all over him. A sheriff comes by the car, but he only makes sure the group is sleeping. At dawn Sal witnesses a white horse emerge from the jungle, pass their car, and go back into the jungle. Dean thinks that Sal is just dreaming when he wakes, but then he remembers that he too had a dream of a white horse.
Back on the road, they stop for gas. Sal freaks out at the sight of all the jungle bugs gathering at his feet. Dean's and Sal's bodies are also soaked in the mixture of blood from dead bugs and their own blood, drawn by mosquitoes during the night.
They finally reach the mountains, where they observe the native Indians. They meet a small Indian child and talk to her for a while, trying to understand the differences between her and them. The Indian children attempt to sell them small crystals along the side of the highway, and Dean and Sal are confused and enamored with this exotic culture, so totally different and separated from the world of white America. Dean gives his pocket watch to one of the girls, and they are in awe of him. Sal compares him to a prophet who had come to save them. As they leave the children, Dean declares that his heart is broken to see them go. They continue traveling through the mountains, taking in the simple, primitive towns that go by. Sal muses that these towns are so cut off from the rest of the world that they do not even know that "a bomb had come that could crack all our bridges and roads and reduce them to jumbles, and we would be as poor as they someday."
They enter Mexico City at dusk and take in the city. It is a place that seems to move and never stop, more than any other town they have ever seen. To Sal, Mexico City seems to be "one vast Bohemian camp." They spend all night just walking through the town, taking it all in, a "holy walk," as Sal describes it. Then, Sal gets sick. He has dysentery.
Sal spends the next few days in and out of a sick daze in bed. Dean tells him that he is going back to New York after getting a cheap divorce from Camille. Stan will stay in Mexico City and care for Sal while he is sick. When Sal breaks his fever and recovers, he immediately thinks about what a "rat" Dean is for leaving him sick in Mexico. But then he understands the complex life Dean leads, "his wives and woes."
Part Five begins by recounting Dean's journey home from Mexico. His car finally died in Lake Charles, Louisiana, and he wired money from Inez to get back to New York. After taking Inez to New Jersey and marrying her, Dean suddenly jumps on a bus for San Francisco to live with Camille and his two children. Dean now has been "three times married, twice divorced, and living with the second wife."
Sal returns to New York in the fall. There he meets the girl he had always wanted. They decide to move to San Francisco and to write Dean to tell him. Dean writes back with an eighteen-thousand-word letter. He tells them that he wants to come to New York to help them pick out a truck that will carry them and their "beat" furniture all the way to San Francisco. Dean shows up too early, though, and Sal has not been able to save enough money.
Dean has been reading Proust and has very many things to talk about, including the way they parted in a "fever" in Mexico. Dean wants to bring Inez back to San Francisco, where he is still living with Camille, but Inez wants to have nothing to do with him and throws him out. Dean gets a letter from Camille, wanting him to return. Sal realizes that Dean has settled with Camille and will spend his life with her. Sal thanks God for Dean's life.
Remi Boncoeur comes to New York and takes Sal and his girl, Laura, to the opera. Dean is preparing to leave New York for San Francisco and wants to ride in Remi's Cadillac to Fortieth Street. But Remi will not have it. The last time Sal sees Dean is as he walks down the street, receding in the back window of the Cadillac as Sal drives away. The book ends with Sal reminiscing about Dean as he sits on a river pier in New Jersey, thinking about the American landscape he had traveled across so many times.
To Dean and Sal, Mexico seems to be the promised land that they were looking for on their many journeys. For Sal, Mexico represents the best way out of the conventional white American life. The beer and cigarettes are cheap, they can smoke huge amounts of dope, and they can visit whorehouses anytime they wish. All of this costs little money, and even more importantly, the police and the citizens of Mexico only watch, enthralled by the behavior, allowing it and encouraging it-perhaps because they are Americans. This culture has its own norms, and it is unclear why the travelers should be expected to worry about or even to know about conventional Mexican life.
Sal and Dean seem to have no knowledge of Mexican culture and instead see the land around them only in terms of their own situation. The people's poverty, instead of a hardship, seems to be complete freedom. Just as with African American culture, Kerouac's characters again invert the traditional understanding of the repression of racial marginalization and poverty, instead presenting the life of these Mexican people as being gloriously free from the pressures of work and money that are experienced in America. For them, the primitive nature of Mexico is its best feature. Unlike their American journeys, Sal and Dean see their trip to Mexico as a trip to the source of life. Mexican culture seems not to have been touched or corrupted by modernity. In Mexico, there is nothing to run from or to. It is only a culture to be embraced because it seems to stand outside of time and history.
The culture that Dean, Sal, and Stan experience in the mountains of Mexico stands outside of anything they have ever seen. Realizing that the road they are on is itself a modern construction just ten years old, however, Dean begins to understand that even wilder forms of life live beyond the highway. Yet, because they are still white American men, they may not be able to leave the highway to discover the Mexican subcultures. There remains a divide between what they want to experience and what they are able to experience. Sal despairs in his realization of what the road might mean for such seemingly pure cultures. He thinks about the invention of the atomic bomb, a symbol for the great destruction that modernity has brought, and despairs that one day the roads and bridges of culture will be destroyed along with the possibility of a pure and free existence.
Their experience in the Gregoria whorehouse provides Sal and Dean with one of their most amoral moments in the novel. During the day they consume massive amounts of alcohol and drugs, and the constraints of conventional society seem to no longer enter into their decisions at all. They have sex with young girls from different cultures and believe that this is what a pure culture can offer, the pure moment of experience. Only a brief moment or two of reality comes into Sal's mind when he sees the fifteen-year-old black girl. When she is sweeping the floor, he begins to understand her poverty and some of the realities of her life. Even so, there remains a divide between the two cultures that Sal cannot overcome.
Their arrival in Mexico City seems to be a revival of their previous experiences. Mexico City appears to be a "beat" city, and the reader can imagine the same kinds of activities and adventures that have characterized the rest of the novel. This final adventure might bring some closure and final understanding to Sal. Instead, Sal becomes sick with dysentery, Dean leaves, and the rest of the stay in Mexico receives no mention. In the beginning of Part Five, they are all back in America, having experienced the culture of Mexico but unable to stay.
The close of the novel finds Sal beginning to settle down with a new love and a new life. Remi Boncoeur's offer to take Sal out on the town in a Cadillac suggests the alternative of a respectable, conventional life. But as Dean shows up with no other intention but to see Sal, Sal wrestles with the feelings of being torn between the two worlds. In the end, Dean cannot enter the Cadillac to go to the opera, just as Sal can no longer follow Dean on the road. Sal has made his choice. As Sal and Dean recede out of one another's vision, one might recall Paul Klee's Angelus Novus, the postmodern "angel of history" as described by Walter Benjamin. This figure has great resonance with Sal's experience.
The novel ends with Sal contemplating the passage of time on a river in New Jersey. For Sal, no ultimate understanding of what "it" is has been accomplished. Sal finally understands that there is no such understanding except that of time moving by and people growing old and fading away. As for Dean, only his memory remains with Sal.