The disappearance of her old friend, Lila Cerullo, 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.
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 neighbourhood 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 store. After a library awards ceremony reveals what Lila has been keeping secret, Elena learns what her friend's grand plans might be.
Entering high school, Elena vows to stay ahead of Lila, academically and romantically. Lila eschews a parade of suitors, choosing instead to focus on her ambitions in the store. Stefano Carracci promises a better future for the neighbourhood but things take a dark turn.
Elena grows tired of Gino while Lila rejects two potential suitors at a cost, and 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 neighbourhood and her family.
On the island of Ischia, Elena runs into the Sarratore family, reigniting her childhood crush on Nino. Back in Naples, Lila's resistance to Marcello's pressing courtship reaches a breaking point. On 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 neighbourhood.
With sales 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 asks her to write a magazine article about her experience. Later, Elena and Lila get unwelcome surprises.
New balances are taking shape now that Lila is Mrs. Carracci. Profoundly resentful against her husband, the young woman finds new ways to carry on pairing off with Elena.
The wedding dress shop in the centre of town exhibits a blown up photo of Lila on her wedding day, generating admiration and gossip among many in and outside the neighbourhood..
Lila starts working in Stefano's new grocery store, but she hasn't stopped bearing a grudge against him, especially now that the business activities linked to his partnership with the Solaras are about to take off.
Elena agrees to taking a beach holiday with Lila, provided they go to Ischia. She knows Nino Sarratore will also be on the island.
Pinuccia leaves Ischia to go back to Rino and the group of five becomes of four. Elena simulates indifference, but there's now a rift between Lila and her, one that goes by the name of Nino.
After the summer in Ischia the relationship between Elena and Lila has become considerably colder. Elena plunges headfirst into studying for her finals, whilst Lila is having to tackle problems of an entirely different nature.
University life in Pisa has deeply changed Elena. Back in Naples for the Easter holidays, she discovers that just as many changes have affected the neighbourhood, and with it Lila's life. Her friend is now totally absorbed by her role of mother.
Close to graduating, Elena is seized by a creative impulse that gives birth to her first novel. She gives the manuscript as a gift to Pietro Airota, her new fiancé, just before returning to Naples, where she finds Lila working in a factory in San Giovanni a Teduccio.
At her book presentation in Milan, Elena unexpectedly meets Nino. At dinner she realises her infatuation for him has never abandoned her and begins to have doubts on her fiancé Pietro.
Pietro meets his future in-laws. They all get on well, though they try to make him change his mind about the civil marriage. Lila sends for Elena: she's in bad health and becoming sicker by the day.
Lila's health is getting worse; her job at the Soccavo plant is burning her out. Elena asks her in-laws to help out; they encourage her to write an exposé to the papers, which ends up stirring up tensions in the unions.
Elena and Lila face difficulties obtaining prescriptions for the contraceptive pill. Adele surprises Elena with an unexpected reception on her wedding day.
Elena embraces the feminist cause and quarrels with Pietro on the subject. Pasquale and Nadia irrupt into Elena's house, bringing chaos and angering Pietro with their behaviour.
On holiday, Gennaro makes trouble with Dede. Elena finds out from Lila that her sister Elisa is seeing Marcello Solara. She travels to Naples to discuss it with Elisa face to face.
Elena's marriage is hitting the rocks. Pietro is detached and treats her like a servant. The domestic situation is further complicated by the presence of Nino, a frequent guest at the Airota household.
Elena meets Nino's family. He shows a great interest for Elena's new book, whereas Pietro has shown none whatsoever. Nino is obliging with him and only covertly attacks him.
Years after escaping to France with Nino, Elena is radiant and wants to make up for lost time with her daughters, who now only obey their Airota grandparents.
Nino has taken an apartment in Naples, but Elena does not forgive his insistent justifications and leaves him.
Lila is now well-liked by everyone in the neighbourhood because of her generosity. Elena leaves her daughters while she and Nino are in New York.
Lila continues to warn her friend not to trust Nino. Elena is upset; what does she know about Nino, and what else does she know about Alfonso and Michele?
Basic Sight is now the centre of the neighborhood; it is there that Elena meets Michele and Alfonso again; it is there that Immacolata would like Peppe and Gianni to work instead of dealing with the Solaras.
Alfonso accompanies Elena to the clinic from Immacolata, and on the way, he confesses to her that he is having an affair with Michele. Meanwhile, Lila gives birth to Tina.
Antonio tells Elena that Nino has cheated on her repeatedly, and she sleeps with him to vent. Three months later, Nino has disappeared, and Elena has to deliver the novel.
Busy with conferences and presentations, Elena neglects her daughters, and Lila takes care of them.