The Complete Review: “His determined narrators have strong, sharp voices and the action -- especially scene by scene -- is reasonably interesting (though as usual for Carlotto the callous violence and gore is piled on pretty thick).”

In Gang of Lovers Massimo Carlotto brings 'the Alligator', Marco Buratti, most recently seen in Bandit Love, out of retirement (as an unlicensed private investigator) -- and pits him against the nasty piece of work that is Giorgio Pellegrini, whose story is familiar from The Goodbye Kiss (as well as At the End of a Dull Day). In other words, Carlotto brings together two characters that have each dominated (and narrated) a separate series, or at least sequence of books; in Gang of Lovers each also gets to have their say: while Buratti's is the lead voice, narrating most of the novel, several chapters are told from Pellegrini's perspective. (Just to cover all the bases, Carlotto adds another narrator to the mix for a few bits too.)
The novel opens with a Prologue, a Swiss woman having gone to some trouble to find Buratti and ask him to take on her delicate case. He's not interested:

I had come to Cagliari to hide out and find some meaning in my life. My new life. Because the life I'd led just a few weeks ago had been swept away by the waves on a beach near Beirut.

The novel then returns to that time, the opening chapter, set in early 2012, finding Buratti involved in a typical complicated extra-legal proceeding which he resolves as best he can. It's not that, however, but rather a more personal matter that then truly upends his world, as he joins two old colleagues from his investigating days, Max and Beniamino, in Beirut.
Shattering their world, Max soon implores Buratti:

Let's start the old business back up. It's the only thing we know how to do.

The determined Swiss woman, Oriana, offers them the perfect opportunity, and Buratti finally accepts the case. Very well-off and married, Oriana had been having an affair with a professor named Guido. Extremely cautious about their trysts -- even buying an apartment in Padua for their encounters (but not trusting her lover with the key) -- she thought she had done everything to keep their affair a secret. But someone made the connection, apparently kidnapped Guido -- and then demanded a ransom from her. But Oriana didn't pay, and Guido was never heard from again. The missing person case got some press attention, but a year has passed and the police hasn't gotten anywhere with it.

Oriana feels a bit bad, because she never came forward to the police, never telling them about the ransom demand (which presumably would have helped their investigations ...); to them, it was just a case of a missing person, not necessarily a kidnapping. And the anxiety about Guido's fate is getting to her: she needs to know what happened to him.

Buratti tells her it's certain that he's dead -- but he's willing to look into the circumstances. With the help of Max and a police contact, he does -- and when they eventually cross paths with Pellegrini they find they've stirred up quite a hornet's nest (and a clever ransom-racket).

Gang of Lovers has some interesting lead characters, including Buratti, with his: "reputation as a crusader, one of those guys obsessed with the truth", and the ruthless control freak Pellegrini. Bit it's an oddly muddled novel, as if Carlotto isn't quite sure what -- or even whose -- story he wants it to be, as suggested also by the narratorial shifts. The case is an odd one too, in that the basic outcome -- what became of the professor -- is indeed pretty clear from the outset, and Carlotto doesn't even offer misdirects that might suggest alternative outcomes.

Carlotto does a lot well. His determined narrators have strong, sharp voices and the action -- especially scene by scene -- is reasonably interesting (though as usual for Carlotto the callous violence and gore is piled on pretty thick). But it feels like the bits don't all fit properly together, an assemblage of serviceable parts that don't quite add up to a proper story. Carlotto goes off in too many directions, and makes it too easy for himself in resolving everything -- right down to the nice new pad in Padua that Buratti winds up with: throwing that in for good measure suggests -- one more time -- just how absent Carlotto's sense of proportion is throughout this book.