Naples, Italy - The "miracle" of Saint San Gennaro's dried blood turning to liquid in Naples' traditional annual ceremony is hugely significant for the city's citizens, as Tony Grant reports.
Suddenly a series of sharp reports - Bang! Bang! Bang! - echoed around the street.
Pigeons flew startled into the sky. And, just for a moment, the paramilitary policeman holding a trombone looked worried. But they were only fireworks.
So he went on chatting to his fellow black-uniformed officers who were armed, variously, with trumpet, saxophone and drum.
The Carabineri police band was about to lead a procession through Naples in a prelude to the day's main event, the moment when the dried blood of Saint Januarius - or San Gennaro as he is called here - miraculously turns to liquid.
Troubled history
It is a matter of considerable importance to Neapolitans. When the liquefaction fails to happen, they believe great misfortune descends upon this ancient, glorious, decayed and troubled city.
Vesuvius, which in AD79 buried Pompeii and Herculaneum under a mountain of ash and lava, overlooks the place. It is overdue another major eruption.
In 1980, San Gennaro's blood failed to turn to liquid.
Not long afterwards 3,000 people died in an earthquake at nearby Irpinia.
And Neapolitans, through history, have known plague, bombardment and invasion; desperate poverty, starvation and unemployment, as well as the pervasive violent grip of the Mafia, known here as the Camorra.
Procession of saints
The Carabineri band struck up a jaunty tune as the procession got under way. Politicians strutted by in red sashes, student clergy swung the incense with vigour.
Prayers were shouted through a white megaphone. The Cardinal Archbishop of Naples, Crescenzio Sepe, beamed as huge models of the saints - allowed out of the cathedral just for the day - were carried by groups of men perspiring in the spring sunshine.
The figures included Santa Patrizia, whose blood is said to liquefy inside a phial every Tuesday.
Then came the priceless silver bust of San Gennaro himself. Alongside the reliquary, an ornate frame carrying the two small bottles of what is believed to be the dried blood of the saint, who was beheaded by the Roman emperor Diocletian in the fourth century.
Through a square of glass, you could just see a brownish substance inside. Hard to tell, perhaps, from the middle of a heaving crowd, but it looked liquid to me.
Naples is known as the city of blood. The sociologist Franco Ferrarotti says northern Europeans are terrified of the stuff but in Naples "life and blood are so closely entwined".
He talks about crime and the use of knives.
"Blood here is part of life and death, and the people of Naples depend on the blood of San Gennaro to purify their city," he says.
Conjuring trick?
I embark on a long train ride north to the city of Pavia. It is raining so hard, that the dried fields of Lombardy have liquefied completely. They look like lakes.
In the university's department of chemistry Professor Luigi Garlaschelli assembles test tubes, distilled water and chemicals.
This iron chloride, he says, holding up nuggets of brownish stuff, is found naturally in volcanic ground.
He mixes it with calcium carbonate and salt and produces a solid substance which looks like, well, dried blood.
He shakes a little bottle of the material and holds it up with a flourish. It turns to liquid.
So is he saying the great "miracle" is nothing more than a conjuring trick?
"No, this is a self-working phenomenon," he maintains, adding: "I'm not questioning the honesty of the Church".
Crowd anticipation
Back in Naples, there is a tangible sense of excitement and anticipation as 1,000 people begin to fill the pews of the huge church of Santa Chiara.
The narrow streets around have been cleared of traffic. A policeman orders a Vespa driver with three other members of the family aboard, none of them with helmets on, to find another route home.
The procession is on its way and soon the Cardinal will tell the congregation whether or not the miracle has taken place.
Elsewhere in the city a group of young students talk about the patron saint. Five maintain they do not believe in the miracle. Two say they do.
And although there is some talk of the Catholic Church needing to change with the times, none wants to see the San Gennaro tradition brought to an end.
The Cardinal Archbishop wipes his brow and gets to his feet. He speaks of the courage showed by the saint and urges the congregation to find the same courage to fight against the Camorra, an evil force, he tells them, which undermines the dignity of man.
And then: "God loves you," he tells the crowd. "Mary loves you". Dramatic pause. "And San Gennaro loves you too".
A huge roar of applause ripples through the church and then the Cardinal explains that the liquefaction has already happened.
He says the miracle was under way before the procession, when the bottles said to contain the dried blood were removed from the safe in the cathedral where they are kept.
The bells ring and the congregation spills out onto the streets as night falls over the Bay of Naples.
The last ferries of the day head off to Capri and Ischia and lights start to twinkle in the houses on the slopes of Mount Vesuvius.