During the Napoleonic Wars, two French cavalry officers, Armand d'Hubert and Gabriel Féraud, become embroiled in a bitter feud. The conflict begins when d'Hubert is ordered to place Féraud under house arrest for having dueled another officer. Féraud takes this as a personal insult, challenging d'Hubert to a duel. Though the initial confrontation ends inconclusively, it sets the stage for a series of duels that span several years. The two men, driven by pride and honor, clash repeatedly, often amidst larger historical events and changing personal circumstances. Each duel leaves them increasingly more obsessed with their rivalry, impacting their military careers and personal lives.

As the years pass, d'Hubert and Féraud's lives intertwine inextricably through their confrontations. The persistent duels reflect the ongoing turbulence of the Napoleonic era, mirroring the upheaval and changing fortunes of their nation. Both men develop and age over time, with their encounters becoming more charged with history and personal vendettas. Observers and comrades view their obsession with a mix of awe and pity, as it becomes clear that the resolution of their feud transcends mere personal animosity, becoming a symbol of relentless human conflict. However, the ultimate outcome of their protracted struggle only emerges in the latter part of the story, where their fates and choices culminate in a dramatic climax.