Twenty years have passed (the Great War slips by here) as the third generation of Forsytes takes center stage. Jon has grown into an earnest and naive young man who decides to train as a farmer at Holly and Val’s horse farm in Surrey. Fleur has become an impetuous, beautiful, thoroughly spoiled young woman. A chance meeting at June’s art gallery sets the stage for the relationship which will affect the remainder of the series. Fleur manipulates a visit to Holly and Val’s, where she and Jon become infatuated. Aware that a feud exists between their families, but ignorant of the specifics, they promise to hold onto their love forever.

The elder Forsytes continue to hide the details of the family feud from Jon and Fleur. Michael Mont, the perky son of a baronet, courts Fleur and gains the respect of Soames, while Jo hides his ill health from Irene. Belgian profligate Profond discovers the truth behind the feud, courtesy of Forsyte cousin George. He begins an affair with Annette, and drops a bombshell on Fleur: her father was once married to Jon’s mother.

The annual cricket match between Eton and Harrow facilitates awkward encounters. Fleur scrambles to get Jon to the altar before he learns the truth behind the family feud. Before he dies, Jo finally tells Jon the entire story of his mother’s first marriage, her adultery, and her rape. Jon chooses Irene over Fleur, and they plan to move abroad, as Fleur, rejected and hurt, finds comfort from Michael Mont.