The narrative centers on Jake Barnes, an American veteran of the First World War working as a journalist in Paris. Because of his wartime injury, Jake suffers from impotence, a physical reality that forms an emotional barrier between him and Lady Brett Ashley, an independent and charismatic woman whom he deeply loves. Brett is engaged to Mike Campbell, a heavy-drinking and bankrupt Scottish gentleman, yet she remains entangled with other men, including Robert Cohn, a wealthy, insecure writer whose romantic idealism constantly alienates those around him.
The early chapters of the book establish the decadent and aimless lifestyle of the expatriate community in Paris. Jake navigates the cafes of Montparnasse, managing his complicated relationship with Brett while trying to distance himself from Cohn's obsessive and pathetic pursuit of her. Cohn, unable to accept that Brett views him merely as a passing diversion, continually embarrasses himself through his lack of social tact and his desperate romanticism, drawing the quiet contempt of Jake and Mike.
As the summer arrives, the group leaves Paris for a fishing trip in the Spanish Pyrenees, followed by the legendary fiesta of San Fermin in Pamplona. Jake and his friend Bill Gorton enjoy a peaceful few days of trout fishing in the mountains near Burguete, far away from the emotional turmoil of the city. However, this temporary tranquility shatters when they reunite with Brett, Mike, and Cohn in Pamplona for the week of the bull-fights.
The tension within the group escalates rapidly against the backdrop of the noisy, wine-drenched festival. Mike publicly humiliates Cohn for his sycophantic devotion to Brett, exposing the underlying animosity among the travelers. Despite the growing hostility, the group is mesmerized by the magnificent spectacle of the bull-ring, where the young and extraordinarily talented matador Pedro Romero commands the absolute devotion of the crowd through his pure and courageous artistry.
Brett's fascination with Pedro Romero turns into an intense romantic obsession, leading her to run away with the young bull-fighter to San Sebastian. This elopement triggers a violent confrontation when Cohn tracks Brett down and savagely beats Romero, alongside Jake and Mike, before finally departing in disgrace. The impulsive affair leaves Brett shaken, forcing her to realize the destructive nature of her desires and compelling her to send the young matador away to protect him from her influence.
The novel concludes in Madrid, where Jake receives an urgent telegram from Brett asking for his help. He travels immediately to find her, only to discover she has already left Romero and returned to Mike. In the final moments of the story, as Jake and Brett share a taxi ride through the crowded streets of Madrid, they reflect on the tragic impossibility of their love, recognizing that despite how differently things might have turned out, they could never truly have had each other.
