The narrator, Sal Paradise, starts to tell the story: he, with his "intellectual" friends, was a young writer in New York City in the winter of 1947, depressed and bored, when Dean Moriarty arrived in New York City. Dean has just gotten out of reform school, just married a pretty young blonde, Marylou, and they have come to New York City for the first time, from Denver. Sal heard of Dean before from Chad King and was intrigued--Dean used to write Chad from jail, asking questions about Nietzsche. Sal and his friends go to see Dean and Marylou in a dumpy flat in Spanish Harlem. Dean comes to the door in his shorts; he is occupied with Marylou, and he has to make explanations to her. Dean is frenetic, hyper, and full of ideas. He speaks formally, in long, rambling sentences. Sal's first impression of Dean is that he is like a young Gene Autry, a real representative of the West. They drink and talk until dawn.
Dean and Marylou are living in Hoboken, and Dean has gotten a job in a parking lot. They fight, Marylou sets the police after him, and Dean goes to where Sal lives--his aunt's house in Paterson, New Jersey. Marylou has left Dean and gone back to Denver. Sal and Dean talk about writing in intellectual jargon that Sal admits neither of them truly understand; Dean has come to Sal and his friends because he wants to be a writer and a "real intellectual." Sal likes Dean's madness. It is decided that Dean will stay with Sal for a while, and that they will go West together sometime.
Sal and Dean go to New York for a night out, and Dean and Sal's friend, the energetic young poet Carlo Marx, meet and hit it off, talking non-stop. Sal doesn't see them for two weeks; they talk night and day, about writing and poetry and madness, of the people they know--who will all collide in the near future. Sal feels something starting.
Spring arrives, and everyone is getting ready to go somewhere. At the bus station, Carlo and Dean and Sal take pictures in the booth before Dean, proud wearing a new suit, leaves to go back to Denver; his "first fling" in New York is over. Sal gives a rhapsodic description of Dean's abilities as "the most fantastic parking-lot attendant in the world." Sal promises himself that he will follow Dean west soon. He likes Dean because of his exuberance, eagerness, uneducated intelligence, and what he sees as his Western spirit, different from Sal's other friends, "intellectuals" or criminals. Sal feels like Dean is a long-lost brother. Also he admits to being interested in Dean as a writer needing new experiences.
In July, with fifty dollars, having written half of a novel, Sal heads west. Consulting many maps and books, he plans to take Route 6 the whole way--a winding red line from Cape Cod through to Los Angeles. To do this, he has to go to Bear Mountain, forty miles north. He hitchhikes there and ends up on a winding mountain road in pouring rain, with few cars passing, cursing himself for being a fool. Finally a couple picks him up, and the man suggests a more sensible route; Sal knows he is right. He has to go back to the city--where he started from 24 hours ago. Anxious to get west as fast as possible now, he spends most of his money and takes a bus to Chicago the next day.
On the Road is a novel of characters more than of plot, of moods and places, visions described, and above all, the unceasing movement of the characters. It is all centered on the hero, Dean Moriarty. Here the scene is set, with descriptions of Sal's life before Dean, and foreshadowing of their sadder, older lives after this period. In the first sentence, Sal says that he has just split with his wife and recovered from a serious illness. He feels depressed and tired, stagnant. Dean's arrival and personality spark everything into motion. Sal has always dreamed of the West, where he has never been, and Dean, the personification of Sal's dream of the West, arrives. The theme of ideas of the East--intellectual, stagnant, old, saddened, and critical--versus ideas of the West--passionate, young, exuberant and wild--starts here; characters are often described with the attributes of the places which they are from--or rather, Sal's idea of that place (See descriptions of Dean and Marylou). Both Dean, "Western kinsman of the sun," and the West, for Sal, are new horizons, wild, open and free.