Julio Desnoyers’s father, Marcelo, angered by his nation’s participation in the Franco-Prussian War (1870-1871), immigrates to Argentina. There he helps a vital Spaniard named Julio Madariaga (nicknamed the Centaur because of his lust for life and his many illegitimate offspring) carve a ranch out of a wilderness. In the process, they defeat or win over the Indians, but eventually they build an empire and make a fortune. Desnoyers experiences the splendor of turn-of-the-century Argentina, with its multicultural population and its potential for growth and development. Eventually, Desnoyers marries Madariaga’s daughter, Luisa, and oversees the financial management of the estate, converting where possible Madariaga’s intensely personal and erratic methods to more methodical and efficient ones. The accidental death of Madariaga’s only legitimate son leaves Desnoyers as Madariaga’s principal heir, with a fortune at his disposal. His German brother-in-law, Karl Hartrott, elopes with Madariaga’s second daughter, Elena, much to her father’s consternation; after a period of ostracism, Karl finagles his way back to the ranch and into an inheritance. When Madariaga dies, the German and French sides of his family decide to return to Europe. Desnoyers does so under pressure from his wife, who is disturbed that their daughter Chichi is growing up a wild savage, riding the range alongside her grandfather as if she were the son he lost.

The Hartrotts ingratiate themselves with the German nobility and assume the haughtiness and pretensions of the German aristocracy, while the Desnoyerses became an established part of Parisian society. A visit to their German relatives confirms the Desnoyerses’ negative feelings about them. Desnoyers wastes a fortune on grand antiques sold at bargain prices in auctions and fills up a castle with ostentatious wealth, including a solid gold bathtub. His son Julio becomes a known roué and is invited to the best homes because of his skill at the tango, the most popular dance of the time; he is also the adulterous lover of many an aficionada of the tango. When, however, he meets Marguerite Laurier, everything changes, and Julio’s artist’s studio becomes the scene of a romance that promises to blossom into marriage, once a messy divorce is past.

Returning from a business trip to Argentina, Julio is disturbed at the dinner table conversations of the German travelers who look forward to war and blame others as the aggressors. He also notices that the behavior of the personnel of the German ship changes; instead of being courteous and eager to please, they are arrogant and commanding. Back home in Paris, he is disturbed that Marguerite is impressed with the good reports he earns as a fearless soldier; she cannot understand Julio’s reluctance to join what for him is a foreign army.

Julio’s father, Marcelo Desnoyers, disapproves of his son’s profligate life and his affair with Marguerite, especially because her husband, Étienne Laurier, is one of his good friends. When news comes that Étienne is seriously injured, possibly blinded in battle, Marguerite abandons Julio and Paris. Later, when Julio traces her to a convalescent home, he finds her nursing her husband. Though she cannot deny her continued love for Julio, she finds a deeper commitment to a brave patriot who loves her dearly and whose sacrifice for his country demands her courageous support. Marcelo is pleased that the affair is over, but Julio, distraught, joins the French army and flings himself into conflict with an abandon that wins him the hearts of his comrades and the respect of his superiors.

When the rich of Paris flee south to escape the invading Germans, Marcelo travels north to protect his castle from looting. He assumes that civilized rules of confrontation will be in force and that civilians will go unmolested. Instead, he finds Germans executing civilians, raping young women, shooting babies, burning villages, defacing property, and engaging in wholesale looting. An encounter with a Hartrott offspring saves Marcelo from certain death, but cannot prevent him from having to endure German officers disporting themselves lewdly, defecating on his valuable furnishings, and participating in acts of perversion and sadism. As a landowner and victim, Marcelo cheers the French resurgence at the Battle of the Marne and makes his way safely back to Paris and security. Later, his growing pride in his son’s heroism makes him seek out Argensola, his son’s companion and manservant, and look with greater forgiveness on the indiscretions of Julio’s youth. Through the influence of Senator Lacour, whose son René is engaged to his daughter Chichi, Marcelo visits Julio in the trenches and observes the nightmare of trench warfare at first hand. News of his son’s injury makes him fear for Julio’s life, and only shortly thereafter he receives news of his death. The old man’s final trip to the front is toward the close of the war, as he seeks his son’s name on a mass grave near the spot where he died. Marcelo realizes the futility of his wealth, for it was not able to prevent the loss of his son. His grief is mirrored in that of his sister-in-law, Elena, whose strong, unquestioning support of the German cause results in the loss of two sons and the injury of a third. Only the young, among them Marcelo’s daughter, Chichi, can look to the future with confidence.