In its third chapter, The Return of the Soldier retells Chris's long-ago courtship of Margaret through a flashback. As with the rest of the novel, Jenny narrates the flashback and comments on events in her own narrative voice; but she tells the reader that she's not talking from her own experience but rather relating what Chris has told her.
On a prose level, this flashback mirrors Chris's psychological entrapment in his youth, as well as the novel's thematic concerns about the disappearing past. Although Jenny and the reader know that Chris is now married and is a soldier in WWI, the vivid and detailed flashback shows how important Chris's earlier relationship with Margaret was and how intensely he still remembers this period in his life despite the intervening years. Moreover, the flashback establishes that the uncomplicated love and happiness Chris experienced through Margaret has no analog in the infinitely more difficult present. It thus helps reinforce Jenny's sense of the past as an unspoiled, simple era inherently distinct from modern life.
This flashback ends at the peak of Chris and Margaret's love, further reinforcing the difference between past and present. But Margaret's later description of the affair complicates Jenny's nostalgic feelings about the past. In Margaret's telling, she and Chris fall out because he is jealous of her interactions with other men and doesn't trust her to be faithful as he would be to a woman of his own class. Jenny also admits that around the same time, Chris's ailing family fortunes forced him to put aside romance and assume a greater role in his father's business. These revelations show that the barriers between Chris and Margaret are not a result of WWI or even other 20th-century developments like industrialization, from which Jenny would like to escape. In fact, their romance flounders in the face of England's notoriously stratified class system, which has dominated their society for centuries and which Jenny, as a member of the landed gentry, respects. While Chris's flashback creates a nostalgic vision of a halcyon past, later additions to the story cast doubt on this way of viewing the world.
