In 14th-century France, the knight Jean de Carrouges and the squire Jacques Le Gris, once close friends, become embroiled in a bitter rivalry. Jean, a respected warrior, feels slighted when his former comrade, the well-educated and charming Jacques, gains the favor of the local Count Pierre d'Alençon. The animosity between them intensifies when Jacques is awarded the estate promised to Jean by the Count. The situation escalates further when Jean marries Marguerite de Thibouville, a noblewoman with a substantial dowry, hoping to restore his fortunes, only to feel wronged yet again by Jacques's continuing ascension in the court's esteem.

The conflict reaches its peak when Marguerite accuses Jacques of a heinous crime. Marguerite's allegations are a direct challenge to Jacques's honor, and he vehemently denies the charges. With the legal and social frameworks of the time pitted against her, Marguerite's courage and resilience are tested as she navigates the repercussions of her accusations. As the truth seems elusive and justice uncertain, the disputants place their fates in the hands of God through the ordeal of combat—the last legally sanctioned duel in France's history, which becomes a spectacle that will determine the destinies of all three individuals involved.