Having adapted Elena Ferrante’s Neapolitan novels over three superlative series so far, My Brilliant Friend comes to a conclusion with its take on the fourth and final book, The Story of the Lost Child. Like its outstanding previous seasons, this Italian drama continues to be rich, sumptuous and deliciously overwrought, but at the same time thoughtful and surprisingly delicate. This beautiful take on Ferrante’s work has done nothing but impress since the very beginning, and it goes out on a high.

For the first time since season one, Lenù and Lila have been recast, with Alba Rohrwacher replacing Margherita Mazzucco and Irene Maiorino taking over from Gaia Girace. We rejoin Lenù in the late 1970s, when her writing career has truly taken off. As she travels Europe to give readings and speeches, her affair with Nino Sarratore (now played by Fabrizio Gifuni) is all-consuming, to the extent that she wonders if she loves him more than she loves her own daughters. The question of whether she loves him (or anyone) more than her work, however, remains an unspoken one, though it is at the heart of this tale.

Italy is in a state of violent political upheaval and reform, shown in montages of archive footage, but also in the changing natures of the people in this story. This sense of a tectonic shift, historical and later very literal, is mirrored in Lenù’s life, as she leaves Pietro and his family in Florence and drags Dede and Elsa around the country, trying to find a safe port in the storm of her tumultuous romance. After catastrophic rows with her own mother and Pietro’s mother Adele – and what a clash that one is – there is no surprise about where she eventually comes to rest.

In this season, there is a lot more of Nino, which is frustrating at times: the man is a liar and a manipulative hypocrite, and it takes a long time for him to fall from grace in the eyes of Lenù, no matter what he puts her through. This frustration is compounded by the fact that in the early episodes, there is a lot less of Lila: this is Lenù’s perspective, after all, and she is avoiding her friend from the old neighbourhood in Naples, ignoring years of messages and phone calls, until she can no longer keep away. When Lila does return to the main story, it is long overdue, and her acidic charisma is a firework on the screen. The friction of their friendship, destined to repeat its destructive pattern of push and pull, is one of the most intricate and complex relationships I have seen depicted on screen.

Each episode of My Brilliant Friend feels like a film in miniature. It takes a confident, artistic approach to depicting the passage of time, unfurling like a languid animal. Sometimes, one decision will be considered for a whole hour, and then perhaps it will be acted upon, or perhaps not. Days pass slowly, but whole years pass in a flash. It is an exercise in delayed gratification – Lenù does not return to Naples for six years – but it is so compelling that you don’t want to miss a moment, even if that moment does involve Lenù inexplicably pining over Nino yet again. Much of the action, if you can call it that, is incited by telephone calls, from borrowed moments on someone else’s landline right through to the final few minutes of the whole thing: that ringing iPhone as Lila’s son calls Lenù to ask if she has seen his missing mother. At times this brings a narrow, stagey, theatrical feel to it, which perfectly complements the expanse of social change and the passing decades.

To take a story from the 1970s through to the 00s in just 10 episodes, and to do so convincingly, requires a special effort. Happily, this is one of the finer dramas of the past few years. It comes to an end circling back to where it began, with an older Lenù wondering where her friend has gone. It is startling to realise how little has been resolved, how many threads have been left to hang in the breeze. But, to loosely paraphrase Lila, who makes a similar point towards the end of this stunning saga, to tie things up neatly would be the stuff of bad novels. This is not taken from a bad novel, but even so, plenty of good novels have been made into bad TV series. This is a testament to its source material, but also a gorgeous wonder of its very own.