The disappearance of her old friend, Lila Cerrullo, causes 60-year-old author Elena Greco to reflect on the early days of their friendship in 1950s Naples, when Elena and Lila are two very different girls at the top of their class. When the girls discover the lair of Don Achille, a criminal figure who controls the neighborhood, they decide to confront him.

As fourth grade draws to an end, Elena and Lila fight with their families for the chance to continue their education. Later, a trip out of town becomes a day Elena will never forget, and a death changes things in the neighborhood forever.

Now a teenager, Elena grapples with the onset of puberty, her studies, and her friendship with Lila, who now works in her family's shoe-repair store. After a library awards ceremony reveals what Lila has been keeping secret, Elena learns what her friend's grand plans might be. Lila takes a stand against the dangerous Solara brothers.

Entering high school, Elena vows to stay ahead of Lila, academically and romantically. Lila eschews a parade of suitors vying for her affection, choosing instead to focus on her ambitions in the shoe shop. Promising a better future for the neighborhood, Stefano Carracci invites Elena, Lila and their families over for New Year's Eve, but things take a dark turn.

Elena grows tired of Gino, while Lila rejects two potential suitors at a cost. A rare outing into the city turns violent. Elena worries about not being there for Lila after accepting an invitation to spend the summer away from the neighborhood and her family.

On the island of Ischia, Elena runs into the Sarratore family, reigniting her childhood crush on Nino, who is at odds with his father, the charming Donato. Back in Naples, Lila's resistance to Marcello's pressing courtship reaches a breaking point. On the day of Elena's 15th birthday, an unexpected encounter leaves her shaken.

Elena returns to Naples to find Lila has made a romantic connection with Stefano, despite the looming presence of Marcello. As Lila embraces a more glamorous life at Stefano's side, Elena warns her about what people are saying around the neighborhood. Later, in hopes of keeping up with her friend, Elena encourages one suitor and rebuffs the advances of another.

With sales of Cerullo shoes lagging, Stefano cuts a business deal with the Solaras against Lila's wishes. After Elena gets kicked out of a class for voicing her opinion, Nino encourages her to write an article for his magazine about her experience. Later, Elena and Lila get unwelcome surprises.

After Nino's unexpected appearance at her book presentation in Milan, Elena realizes her childhood crush never really abandoned her, and doubts begin to form about her fiance Pietro. Later, a scathing review leaves Elena questioning herself as a writer.

A nervous Elena introduces Pietro to her family, and, though he instantly charms his future in-laws, Immacolata rejects their plans for a civil wedding ceremony. Months later, Lila falls ill due to the deplorable conditions at the Soccavo factory and makes Elena promise to take care of her son Gennaro if anything happens to her.

Concerned about Lila's worsening health, Elena seeks advice from her future mother-in-law Adele, who encourages her to write an expose on the Soccavo plant and the mounting unrest between rival unions. After several doctors' visits, Lila becomes determined to move back to the neighborhood despite being viewed as a pariah.

After a tense argument about plans for a family, Elena and Pietro marry in town hall, and later, are surprised with a reception organized by Adele. Though she had hoped to concentrate on her next book, Elena gives birth to a daughter and struggles to find time to write.

Following news of a murder in Naples, Pasquale and Nadia turn up unannounced at Elena's house in Florence, further fuelling discord with her husband. Meanwhile, Elena suspects all is not right with Lila when she's asked to take Gennaro on their summer beach trip.

On holiday, Elena grows increasingly exasperated with Gennaro and after receiving shocking news about her sister Elisa, she cuts the family trip short to travel back to Naples. Later, tensions mount at a dinner with the Solaras, and Pietro shares his unvarnished opinion of Lila with Elena.

Elena's marriage is more and more in crisis, Pietro is distant and she feels treated like a servant. One day, Nino Sarratore shows up at the Airota's door. He and Pietro become friends and say goodbye with the promise to meet again. Elena anxiously awaits their next meeting and finally resumes writing.

Elena and Pietro meet Nino's family. Nino gives Elena his feedback on the manuscript, when he discovers that Pietro has not read it he shows hostility towards her, but in a veiled and underhanded way. Pietro's reaction to Nino's passive-aggressive attacks only confirms Elena's doubts about her husband.