A lot happens in this novel and the friendship itself has a much more central role in the relationship between the two women. During the story, Lena moves back to the old neighbourhood to live in apartment above Lila. Book three ended with Lena leaving her husband and children to be with Nino and this relationship and its outcomes form the backbone to this last book. Actually the relationship of these three characters - Lila, Lena and Nino is really what the whole series is about, not just the friendship between the two women. Lena has become a very successful writer, and Lila still continues to own and manage the computer business she and Enzo established in book three. But the Solara brothers never go away, always a menacing presence, as is the political unrest.
I have never really liked any of the characters in these novels, and that has been part of my ambivalence over these novels. I still don't really, but the quality of the writing does continue to be outstanding.