‘The Cold Summer’ is the latest bestseller from Italy’s most celebrated anti-Mafia judge, politician, and essayist Gianrico Carofiglio. Although the summer of 1992 was indeed molto fredda across Sicily and Southern Italy, it was moreover a cold summer because of the murder of Carofiglio’s colleagues and friends in Sicily, Giovanni Falcone and Paolo Borsellino, and his new book is dedicated to them. Falcone and his wife were killed by a huge bomb under the motorway close to Palermo’s airport. Borsellino and his escort were hit as he visited his elderly mother in a downtown apartment.

In strange coincidence, at about the same time, Cold Summer became the code name for one the most successful anti-Mafia operations in Puglia, the southern heel of Italy – the latest dolce vita destination for Italophilic Brits abandoning Tuscany and Chiantishire for sunnier climes and richer wines.

Carofiglio’s new novel dramatizes the true story of Operation Cold Summer – only a few names and locations are changed, the author tells me, but much of the action is as it really was. In his canon of novels set in southern Italy, now more extensive than the chronicles of Sherlock Holmes, it is his most documentary and realistic to date.

The story turns on a kidnap and murder which allowed investigators to turn a prominent clan leader informant. He led one of the new Mafia groups in Puglia, Societa Nostra, and his new super grass status was the first major coup for the police in the region. The rhythms of the interrogation, which last over several months, are fascinating as the cornered mafioso reveals all the different gangs and locations – and these names are not fictionalized.

In the 1980s the gangs in Puglia were feeling the heat of the Camorra of Naples and Cosa Nostra of Sicily – which had become dominant in narco crime across the Mediterranean since the breaking of the French Connection of the Marseilles and Corsican gangs in the early 1970s. “Learning from the Camorristi prisoners they met in jail, the Pugliesi decided to build their own equally robust structure, based on strict codes of honour, and silence, enforced by extreme violence,” Carofiglio told me.

Although the Pugliesi were late on the scene, they adopted ancient mafia rituals that made new recruits ‘sworn men’ – the pricking of fingers, mixing of blood, and oaths taken on the burning image of a saint. It was an odd rite of passage. Carofiglio: “We found the instructions for this in the effects of one of the Mafiosi we detained – even the handwriting seemed very childish.”

Meeting Gianrico Carofiglio is like encountering one of the good guys from the Inspector Montalbano series. He is charming, urbane, full of dry understatement and the sense of assured nonchalance summed up by the untranslatable epithet ‘dinsinvoltura.’ Though his conversation is peppered with literary allusions, Scott Fitzgerald, George Orwell, Italo Calvino, Bertrand Russell, and his beloved Sherlock Holmes – to name but a few – he is full of light and good humour.

In London, during his promotion of the English publication of ‘Cold Summer,’ we chatted across a huge range of subjects – Mafia and Puglia, the magistracy, the police, the chaos of politics in Italy, including his bruising five years as a member of the Senate in Rome, and great colleagues and rivals. It was as if we were in his favourite haunt, the Café Boheme in downtown Bari, the hang-out of many of his friends, and inspirational haunt for many of his characters.

Born in Bari in 1961, Gianrico was drawn to the law – especially the investigating magistracy. He would come to work alongside investigating detectives, either from the state police, the Polizia, or Carabinieri. When he decided not to run for the Senate for a second term, he returned to the magistracy. His novels which first appeared in 2002 with ‘Involuntary Witness’ have now become best sellers across Europe. “I had to decide to write full time – after all I couldn’t tell the tax man my second job was ‘judge’.”

The hero of his first stories is Guido Guerrieri, a down at heel, divorced, defence lawyer. A sometime essayist and commentator, he likes jazz, world music and opera – and books. “Yes, he is an alter ego of sorts. But he works for the defence in trials, which always fascinates me as I have always been in the public prosecuting office. But I have had to rest Guerrieri as a character. He was far too successful with the girls, and I was becoming jealous.”

The protagonist of ‘Cold Summer’ is a Carabineri detective, Maresciallo Pietro Fenoglio. I said it seemed almost counter-intuitive to cast such a figure as a super sleuth – given the rather stolid, military profile of the Bene Merita, the Corps of Carabinieri. “Not at all, some of the bravest men I have come across have been Carabinieri, and some of the most ingenious.”

Fenoglio is firmly of the political centre-left, and wears his culture lightly. He is often to be found reflecting on the thoughts of George Orwell, Calvino and Bertrand Russell. And the quotes and nostrums of Sherlock Holmes, who has a cult following among so many Italian literati such as Carofiglio and Umberto Eco.

Again, the inspiration is from real events: “During Cold Summer, we were investigating the background to a number of Mafiosi we had on remand. One day I went to the prison and was met by a Carabinieri, who gave me a list of books, articles and references about the community and society in our case. He is one of the most intelligent investigators I have ever met – he was just an agente, a private, not a sergeant or NCO.”

Fenoglio first appears in a novella ‘Una Mutevole Verita’ (a mutable truth), commissioned for the 200th anniversary of the foundation of the Corps. “The Commandant General asked four writers for a story about a different period in Carabinieri history – one of the others was Andrea Camilleri (creator of Inspector Montalbano).” One wonders if the Commissioner of the London Met would show such flair and imagination.

Carofiglio is sanguine about the power of the Mafia he has spent so long fighting in law and in literature, both as a former judge and current commentator. “The Mafia certainly haven’t won, but they’ve changed. The old organisations of Sicily and Puglia, who created a blood bath in their wars of the 70s and 80s are in retreat. Many of the big bosses are in jail, those headed by Andrea Montana and Toto Riina.”

Italy now has one of the lowest murder rates in Europe, he says. In 1991 to 92, the year the Corleonesi murdered Borsellino and Falcone, there were more than 2,000 organised crime murders. Last year Italy reported 320 major homicides.

Groups like Sacra Corona Unita – United Holy Crown – have been exaggerated by international media, he muses. “Their ground was the south of Puglia round Lecce, and they were forced to flee to the Balkans.” Equally the Albanian gangs never had the grip they have in Northern Europe. “They didn’t understand the culture and didn’t make the necessary deals with local bosses.”

The tough clans of Puglia, like the Societa Foggiana, and the Rosa, around which the new novel is based, fought hard and dirty throughout the eighties and nineties. “Take the town Cerignola, between Bari and Foggia, a horrible little town of about 60,000. In one year alone they had more than 40 Mafia murders.”

The Mafia groups have changed, with mergers and takeovers across the international scene. The most powerful traditional Mafia is now the ‘ndrangheta of Calabria, “powerful, secretive, tight family units and very, very violent.”

Perhaps more bruising even than his time as a prosecutor was his five year term in politics as a Senator for the leftist Democratic Party in Rome. Politics in Italy are a wreck after the last elections, he says. “The Democratic party has been destroyed.”

“By the narcissism of (former Prime Minister) Matteo Renzi ?” I ask.

“Yes, like Tony Blair. This government, an alliance of the right wing League and leftist 5 Star Movement, doesn’t function – it can’t because the 5 Star Movement isn’t a proper party. It is a collection factions fighting each other all the time. Their mayor of Rome, Virginia Raggi, will be lucky to escape a prison sentence.”

The sense of civic gloom does not extend to his beloved Bari. The city of his birth is a major character in his novels, like Stockholm in the best Swedish noir and Los Angeles to Raymond Chandler’s Philip Marlow stories. But unlike Chandler’s LA, Carofiglio’s Bari is no villain. It is always a source of light in his novels. One of the central features of the stories – a wonderful cocktail of fact and fiction – is the legendary Teatro Petruzzelli, the last major opera house to remain in private hands. In 1991 it was blown up. “They were crazy – it was an insurance job in which they intended to burn down only a wing. They put packets of explosive inside tins of petrol, to avoid detection. But they overdid it, and blew the whole thing up. But we got them, and we managed to put the leaders of the whole scam in jail.”

After 18 years, it reopened. But running costs are enormous. Two years ago, Carofiglio took his turn as president of the trustees.

“You must join me next season,” he says with a broad grin. “Yes, Bari is a fine place. The city really works, quite unlike when I was a boy.”

His articulate optimism and disinvoltura are infectious. He sums up his past achievements as investigator and story teller with his favourite Sherlock Holmes aphorism: “Nothing is more deceptive than an obvious fact.”

Which sounds even better in Italian: Non c’e piu grande l’inganno che quello piu ovvio.”