Jake Barnes and his expatriate friends live in the topsy-turvy, hedonistic (sensual and self-indulgent) world of post-World War I Paris. There, they occasionally work, but spend most of their time partying, drinking, and arguing. From Jake’s perspective, we meet the cast of characters that populates his story: the most important among them are Robert Cohn, a weak-willed, down-on-his-luck Princeton grad and unsuccessful writer, and Lady Brett Ashley, an exciting, beautiful, and unpredictable British divorcee.
Although Jake and Brett are actually in love, they aren’t together, presumably because a mysterious war wound has rendered Jake impotent. Cohn falls in love with Brett (as everyone does) and, despite the fact that she’s not terribly impressed with him, she secretly goes on a trip with him to the Spanish resort town of San Sebastian. Cohn is infatuated with Brett – he’s completely smitten. We’re talking truly, madly, deeply in smit. Unfortunately for Cohn (and for everyone, for that matter), Brett is engaged to a wealthy, charming, and utterly inept drunkard named Mike. Jake’s whimsical friend Bill returns to Paris from a trip and a plan is born: everyone agrees to decamp to Spain for some fishing and the running of the bulls in Pamplona.
On their brief fishing trip, Bill and Jake have a splendid time communing with nature and with each other, but the relaxation quickly comes to an end. They return to civilization and meet up with Brett, Mike, and Cohn in Pamplona for a weeklong orgy of bullfights, alcohol, and high drama. Jake has a true passion (aficion) for bullfighting, but everyone else is simply there to have a good time. Brett begins a rather scandalous affair with a passionate and talented young bull-fighter, Pedro Romero. Jake feels terrible for many reasons – among them is the fear that he has corrupted Romero in some way by introducing him to Brett. Cohn’s thwarted infatuation with Brett leads to arguments with everyone and, finally, he beats the unfortunate Romero to a bloody pulp. As the fiesta winds down, everyone leaves Pamplona in various states of anxiety, depression and frustration.
Jake heads to San Sebastian, where he intends to decompress alone for a while. Unfortunately, desperate telegrams from Brett arrive immediately. He goes to her in Madrid, where she is alone, having sent Romero away. For the first time, we see Brett truly vulnerable, afraid, and guilty. The future looks just as bleak – Jake and Brett agree again that, even though they love each other, they can’t be together.