Elena precisa lidar com a puberdade, os estudos e sua amizade com Lila, que agora trabalha na sapataria de sua família; os encontros cada vez mais frequentes das garotas com o sexo oposto fazem Lila se posicionar contra os irmãos Solara.

Ao entrar no Ensino Médio, Elena jura ficar à frente de Lila, acadêmica e romanticamente; prometendo um futuro melhor para o bairro, Stefano Carracci convida Elena, Lila e suas famílias para uma festa de Ano Novo.

Depois de saber que sua amiga de longa data, Lila Cerullo, desapareceu sem deixar vestígios, a escritora Elena Greco relembra sua turbulenta amizade em uma perigosa e fascinante Nápoles, Itália.

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.

With Lila on her honeymoon on the Amalfi Coast, Elena struggles to handle school and her relationship with Antonio. When Lila returns with visible bruises on her body, the two girls revert to their natural closeness and Lila’s will to take revenge against her husband grows. Elena continues to be bewitched by Nino Sarratore’s charisma but chooses not to mention him to Lila.

Elena's relationship is threatened when Antonio discovers she has asked the Solaras' help to keep him from doing military service, while Lila remains rebellious in her marriage to the often-violent Stefano. After a photo of her is exhibited at a wedding dress shop in the center of town and becomes the subject of much gossip, Lila makes a bet with Elena about how the whole affair will end.

Following her formative summer on Ischia, Elena throws herself into her studies and looks towards a future outside of the neighborhood. After a brilliant finals performance, Elena happens upon Lila, who is working at the shoe store and has grand plans for a fresh start. As Elena leaves Naples to commence her prestigious university studies in Pisa, Lila decides to leave Stefano and moves into a modest apartment, but the failings of her plan soon emerge.

Three years into her time in Pisa, Elena has developed into an elegant and cultured young woman – but still feels like an outsider. After a consequential breakup, Elena falls ill and is visited by her mother, who has come to nurse her back to health. During the night, Elena takes to reading Lila’s diaries, which were entrusted to her for safekeeping; in these tomes, Elena discovers Lila’s dedication to her new role in the face of Stefano’s increasingly violent behavior.

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.