The novel is a poignant tale set in the 1920s post-World War I era, focusing on a group of American and British expatriates living in Paris who travel to Pamplona, Spain for the annual Running of the Bulls. The story explores themes of disillusionment, identity, and the Lost Generation, with the protagonist, a war veteran, grappling with impotence caused by a war injury. The narrative is steeped in the disillusionment and existential crisis experienced by many in the aftermath of the war, and the reckless hedonism of the era is portrayed through the characters' aimless wanderings and excessive drinking.