Marcelo Desnoyers, disillusioned by his country's role in the Franco-Prussian War, relocates to Argentina. There, alongside the spirited Spaniard Julio Madariaga, he transforms a wild expanse into a thriving ranch, amassing considerable wealth. Despite initial resistance from native tribes, they establish a prosperous empire during Argentina's promising turn of the century.

The Empire's Heir

Marcelo eventually weds Madariaga's daughter, Luisa, and takes charge of the estate's finances. He introduces structure to Madariaga's erratic management style. When Madariaga's only legitimate son dies unexpectedly, Marcelo becomes the principal heir, inheriting a vast fortune. Meanwhile, Karl Hartrott, Marcelo's German brother-in-law, marries Madariaga’s other daughter, much to Madariaga's displeasure, but eventually secures his place on the ranch and a share of the inheritance. After Madariaga's death, the family splits with the Desnoyers returning to Europe, prompted by Marcelo's wife who fears their daughter Chichi is adopting the untamed ways of the ranch.

Contrasting Lives in Europe

While the Hartrotts cozy up to German aristocracy, adopting their airs and ambitions, the Desnoyers integrate into the refined circles of Paris. Their visit to their German relatives only hardens their unfavorable views. Marcelo indulges in lavish auctions, filling his chateau with extravagant antiques, including a gold bathtub. His son, Julio, gains notoriety as a skilled tango dancer and charmer, drawing the attention of many women. However, his relationship with Marguerite Laurier marks a turning point, hinting at a future marriage once her messy divorce is settled.

A World on the Brink

Upon returning from Argentina, Julio is unsettled by the war-hungry conversations among German passengers on his ship, who cast blame on others for impending conflict. The shift in attitude among the ship’s crew, from hospitable to domineering, further alarms him. Back in Paris, Julio is perplexed by Marguerite's admiration for his perceived bravery as a soldier, failing to grasp his hesitance to join what he views as a foreign army.

Love and Duty

Marcelo disapproves of Julio's reckless lifestyle and affair with Marguerite, given her husband, Étienne Laurier, is a close friend. When Étienne suffers severe injuries in battle, Marguerite leaves Julio to care for her husband. Despite her lingering affection for Julio, her devotion to her husband, a courageous patriot, prevails. Although Marcelo is relieved by the affair's end, Julio, heartbroken, enlists in the French army and fights valiantly, earning camaraderie and respect.

The Horrors of War

As the wealthy flee Paris in the wake of the German advance, Marcelo heads north to defend his estate from plunder. Expecting civility, he instead witnesses the brutality of war: executions, assaults, and rampant looting. A chance encounter with a Hartrott relative saves his life, though he is forced to endure the German officers' debasement of his home. Marcelo's spirits lift with the French triumph at the Battle of the Marne, allowing him to return safely to Paris.

A Father's Pride and Loss

Marcelo's pride in his son swells as he hears of Julio's heroics. He visits Julio at the front, facilitated by Senator Lacour, whose son is engaged to Chichi. Experiencing the horrors of trench warfare firsthand, Marcelo is devastated when news arrives of Julio's injury and later his death. Visiting the site of his son's sacrifice, he painfully acknowledges his wealth couldn't shield him from such loss. Elena, his sister-in-law, also mourns deeply, having lost two sons to the German cause. Yet, amid the grief, the youth, including Chichi, remain hopeful for what lies ahead.