Ray and Japhy have a somewhat solemn dinner in Chinatown and then see a group of black preachers lecturing to Chinese families and bums. Ray believes that one particularly effusive woman would make a wonderful preacher were it not for her habit of spitting every few minutes. Japhy, however, is not impressed with her doctrine; unlike Ray, he does not believe that Christianity and Buddhism are - like everything else - "the same." The woman takes special interest in the pair of friends, especially Ray, and comes over to talk to them personally. Just across the street, a group of Chinese youth are working on building a Buddhist temple.
Cody, who had been living at Rosie's place, has now moved back with his family. Ray visits his distraught friend for a few days and agrees to help him pray for her so that - according to Cody - she can get into purgatory instead of hell. In the daytime, Ray jots down the rhyming poems that Cody's children recite. Unfortunately, he says later, he also catches a cold from them that will plague him during his journey.
Finally, it is time to leave; Ray is waiting to sneak onto an evening freight train, but is warned by the switchman that he will be found and thrown off at the town of Watsonville. Ray sneaks aboard and curls up in his sleeping bag, then carefully hides in the weeds until he can sneak on the train again. He does not wake up until it arrives in L.A., a city he finds detestably hot and smog-filled. While he waits for another train to Arizona, he meets an intriguing middle-aged bum who claims to have cured arthritis by standing on his head for three minutes every day. (The narrator admits that he tried this, and swears that it cured his thrombophlebitis).
The Zipper finally arrives, but after Ray climbs on he realizes with horror that there is no entrance for him. By the time he untangles himself from the catwalk on the top of the train it is going too fast for him to jump off. But when he lets go, he remains unharmed - although stranded in an undesirable industrial city all night. Finally he buys a cheap bus ticket to Riverside, but notices that police eye him and his rucksack suspiciously. He pines for the calmness of his mountainside rests with Japhy.
Chapter 17 opens with Ray feeling optimistic about camping out in Riverside, where the air is cleaner, but a man warns him that the police are fierce in this city and will take him in if he tries. Sore and suffering from his cold, Ray knows that he has no choice but to do it anyway. He feels increasingly scornful toward the cops in their shiny cars and the conforming "sheep" that passively follow their orders.
Ray fights his way through the thickets of the highway woods and makes his way to the dried river-bottom. There, he lights a small fire, sets up his sleeping bag on a bed of leaves and bamboo joints, and stands on his head to try and relieve his sinus pain, feeling rather sad. Ignoring the roar of traffic, he eats the food he bought earlier in the day and then begins to pray for his own well-being, for those celebrating the Christmas season, and for Rosie. In spite of his discomfort, he determines that this is the most satisfying and valuable existence he can be living, and wakes up rejuvenated and ready to hitchhike 3,000 miles to Rocky Mount, North Carolina, to visit his mother.
Chapter 18 covers Ray's entire journey from Riverside, California to his home in Rocky Mount; along the way, he meets several colorful characters. After hitchhiking to Beaumont, Ray gets a ride from a Mexican drunkard named Jaimy who makes Ray buy him wine in exchange for a trip to Mexicali, Mexico, but then deserts him before they cross the border. Changing his plans, Ray enters Mexico on foot, only to be yelled at almost immediately for urinating on a man's property. The protagonist is angry at first, but then realizes that he has ruined the spot where the man sits at night next to a fire, and feels guilty. Shortly thereafter, he runs into a Chinese Mexican deaf-mute who warns him, with vehement hand gestures, against sleeping outside. Ray begrudgingly admits to himself that the beggar is right: being homeless is, unfortunately, dangerous.
Ray thoroughly enjoys himself, indulging in the tastes and sights of the vibrantly animated city of Mexicali. He is stopped at the border, though, by suspicious officials who believe that he is hiding drugs in his rucksack. On top of that, he finds out that the Zipper does not run through El Centro after arriving there by bus. Instead, he returns to Mexicali with an amiable Midwestern trucker named Beaudry, where they visit saloons and a brothel before driving to Tuscon. Much to Beaudry's surprise, Ray manages to cook an amazing steak over a self-kindled fire, which leads him to muse over the free-spirited glamor of the bum's life. In fact, despite his fear of being caught and losing his job, Beaudry offers to drive Ray all the way to Ohio, which is much closer to his ultimate destination. As they whiz across the United States, sharing anecdotes and hearty meals, Ray and Beaudry become friends, and they part sorrowfully.
Ray finishes up his journey through this colder and snowier area by bus and on foot to find his mother washing the dishes, just as he anticipated in Chapter 17. He greets and feeds his dog, Bob, and then enters the house where he is welcomed by his mother, sister, brother-in-law and nephew, "home again" at last.
On to Chapter 19, in which Ray elects to sleep not inside near the fire (as his family urges) but rather on the back porch, where he leaves all of the windows open and curls up in his sleeping bag. After everyone has gone to sleep, he sneaks outside, followed by Bob and some other stray dogs, to a forest that he had made a path in last year. The path, it turns out, still exists, and Ray returns to a familiar pine tree, where he meditates for an hour in complete peace: everything is utterly still and silent for miles around. Finally, he returns to the house, warms himself, and goes to sleep.
The next night is Christmas Eve; Ray enjoys the ceremonial masses being broadcast on television, but believes that the scene of his sister and brother-in-law laying out presents for their young son is even more glorious than all the pomp of the church. Late at night, he reads some paradoxical Biblical passages, relating them in his mind to his own Buddhist ideas.
The next week, Ray's mother is attending a funeral and his siblings are working, so is he is alone in the house. He occupies his time in the woods reading, studying, and meditating, returning at night to cook dinner for the family. He creates poetry and prayers, and also shoots basketball using a hoop he sets up. At one point, he feels extremely depressed and throws himself to the ground, but then believes he has come to the revelation that "all the dead," including Rosie and his father, already know: "Believe that the world is an ethereal flower, and ye live." The chapter ends with Ray feeding his cat.
Chapter 20 opens in late January. Ray feels that all of his meditating is beginning to "bear fruit." He has sincere and exuberant faith in the rightness of the universe, and feels no concern for the illusory realm of earth and flesh. In his ecstasy he wants to write to the quiet and modest Warren Coughlin, a very different character than Japhy, Alvah, or himself. As February comes and the weather warms, Ray continues to dream and meditate about oneness and emptiness.
Nevertheless, the narrator cannot completely distance himself from reality: his brother-in-law is annoyed with his idleness, and very few people-with the exception of one old man at the bar-seem to understand or support his lifestyle. Ray, though, does not care in the least about others' opinions, and also believes that everyone is merely jealous of him.
Chapter 21 follows as the weather begins to warm during springtime. Ray continues to meditate outside under the trees. He interacts with his young nephew Lou, creating spontaneous poetry; sometimes, he simply enjoys himself, thinking of nothing. Eventually, Ray begins to have visions and strange dreams, as, for example when he dreams that he refuses to help his mother haul suitcases of gray meat. In real life, he irritates his family by refusing to go for drives with them on Sundays and taking Bob the dog outside without a leash. More practically, though, he signs up to be a summer fire lookout on Desolation Peak in the Cascade Mountains in Washington, just as Japhy suggested earlier in the book.
Ray begins to read meanings into the croakings of frogs and the way that he loses - and then finds - his juju beads. In a flash of insight, he suddenly feels that he really understands that "everything is empty:" that all things are ephemeral, and that it is paradoxical for all tangible things to be comprised of tiny, untouchable atoms. When he tries to explain this to his family, however, Ray is met with scorn and derision. Nevertheless, Ray is ecstatic and feels that he has become a Buddha at last, especially when his visions continue. In one of them, he sees the vision of Dipankara Buddha, a silent figure in a field of flowers, accompanied by the word "Colyalcolor." Furthermore, when his mother becomes increasingly ill, he has a vision of a particular type of rubbing medicine and small white flowers, identical to the ones in the house. After he moves the flowers outside and gives his mother the medicine, she recovers; it turns out that she was allergic to them. Although no one is particularly impressed, Ray claims that he is not impressed either, and that righteousness is the ultimate sin. After this "miracle," Ray leaves his family at last to go back to California.
Chapters 16-21 cover the winter and spring in which Ray travels from California to North Carolina to stay with his family. The protagonist's intention to hitchhike 3,000 miles across the country to his home in inserted with abrupt matter-of-factness at the end of Chapter 15. This stylistic choice mimics the style Kerouac employs in the first sentence of the book about "hopping a freight train" in that it is jarringly random and unjustified to the reader, but perfectly natural to Ray as a free-spirited Dharma Bum.
One of the key aspects of Ray's journey back east is his ability to quickly become friends with those he meets on the road. When Ray meets Beaudry, for example, the two visit Mexicali together and enjoy themselves as old friends would, even though they have just met and despite the fact that they will never see each other again. The underlying theme is that things do not have to be permanent to be valuable. Ray's actions also suggest that - in keeping with the prayer he taught Japhy as they were climbing Matterhorn - Ray genuinely believes that everyone is "equally a coming Buddha." One of his explicit thoughts is that "people have good hearts whether or not they live like Dharma Bums."
Ray's equal compassion for all people extends to the fact that he is unafraid to dabble with Christianity, however impersonally. When home with his family on Christmas Eve, he watches the evening masses not with scorn but rather with detached delight, and when he is sleeping in Riverside he makes sure to pray for those celebrating Christmas. In this sense, Ray actually seems to have a deeper understanding of Buddhism than Japhy does; ironically, his orthodox Buddhist beliefs lead him to be myopic and somewhat anti-Christian. Ray truly appreciates the lecturing of the black preacher-woman that he and Japhy meet after their dinner in Chinatown in Chapter 16; he believes that her "new field" is nothing more than "Nirvana by any other name." He tries futilely to explain to Japhy that "there were things I wanted to tell Rosie and I felt suppressed by this schism we have about separating Buddhism from Christianity, East from West, what the hell differences does it make?" Ray is not guilty of hypocrisy when he asserts, at the end of Chapter 21, that the worst sin is righteousness.
What ultimately leads Ray to the conviction that everyone's religion is equally valid and that all are worthy of compassion is his understanding of the world as an absurd "void" in which differences are trivial and effectively meaningless. He spends a long time meditating on this while he is home with his family and eventually feels that he has finally begun to understand it: "Believe that the world is an ethereal flower, and ye live." In such a bizarre world, seriousness is ineffectual and turned on its head. Ray's driver Beaudry vaguely grasps the value of Ray's strange existence: "Here I am killin myself drivin this rig back and forth from Ohio to L.A. and I make more money than you ever had in your whole life as a hobo, but you're the one who enjoys life and not only that but you do it without workin or a whole lot of money. Now who's smart, you or me?" The idea of "turning reality on its head" is also literalized in Ray's encounter with the once-arthritic bum on the train who advises that Ray "just stand on [his] head three minutes a day, or mebbe five minutes." As absurd as it seems, Ray "vows to take his advice because he is Buddha" and finds that it is actually invaluable in curing his phlebitis. This scene is actually based off of a true encounter in Jack Kerouac's life. After meeting "the Buddha," Kerouac would frequently perform headstands, even in the company of others.
Unfortunately, though, most of the people in the world do not understand Ray's conception of it. One of the major themes of these chapters is Ray's "crucifixion" of sorts - his banishment and denigration by "normal" world forces - that lends his journey a bluesy feel. In many ways the world is against him: the man whose property he urinates on; his family; the police. He remarks mournfully that "everything was far away from the easy purity of being with Japhy Ryder in that high rock camp under peaceful singing stars," and that "either side of the border, either way you slice the boloney, a homeless man is in hot water." Ray also claims that he is a "friend" of dogs, probably because he shares their characteristic of innocent silliness and enthusiasm for life. Thus, when his brother forces him to keep his dog Bob on a chain, it is personally painful. Metaphorically, the chain represents an unforgiving and misunderstanding world, too biased and "serious" to understand Ray's joyful message.