Three summers earlier, on the eve of a couples' trip to Tuscany, Alex calls Poppy to ask if traveling together with Trey and Sarah is a mistake. Poppy reassures him and reflects on how stable everything seems: she is happily dating Trey, Alex is back with Sarah, and everyone has begun to get along better. She remembers an earlier Ohio visit, where Trey met Alex and Sarah at dinner and then attended Mr. Nilsen's birthday party. Trey tries hard, Sarah stays tense, and Betty unsettles Poppy by asking whether she loves Trey the way she loves Alex, forcing Poppy to admit that her love for Alex is singular.

Once the four of them arrive in Tuscany, the villa, wine, and relaxed pace quickly soften the group's awkwardness. Sarah becomes more open, Trey stays warm and affectionate, and Alex contributes his dry humor. As they spend days swimming, sightseeing, eating, and drinking together, Poppy starts to believe the four of them can truly coexist and even become friends. She also recognizes that she may have resisted Sarah partly because she was holding too tightly to Alex.

As the trip continues, the group bonds through meals, games, and late-night conversations. One night, when Sarah and Trey tease Poppy about loving reality TV, Poppy explains that what interests her is how people choose not just a person but a life, revealing how deeply she thinks about compatibility and love. Alex quietly supports her in the moment. Soon after, Alex gets word that Tin House has accepted one of his stories, and the group celebrates, though Poppy has already been feeling increasingly nauseated.

That night, after realizing her period is late, Poppy panics that she might be pregnant. Before dawn, she drives to buy pregnancy tests and returns to the terrace in a state of fear. Alex finds her there before his morning run, sees the test in her hand, and comforts her while she cries. When Poppy worries about what Trey would want and how she could manage a pregnancy alone, Alex redirects her to what she wants and promises that she will not be alone because he will be there for her.

Poppy takes three tests, and all of them are negative. The relief is tangled with something more painful: Alex breaks down crying and admits he does not know what he would do if something happened to Poppy, making clear that his fear is bound up with losing his mother. After that raw moment, Alex pulls back, says Trey seems like a great guy, and leaves for his run. Poppy gets her period soon afterward, and the rest of the trip remains outwardly normal, but she feels heartbroken and understands that wanting Trey, Alex, and the life each represents cannot all fit together. She resolves to stop leaning on Alex and to get out of the way of the future he might build with Sarah, even though she keeps loving him.