They were the streets that Caravaggio and Fillide Melandroni knew well. As did Ranuccio Tomassoni, another of her lovers, part of the demi-monde that populated sixteenth-century Rome. Jealous and possessive, Caravaggio wanted Tomassoni neutered, never to make love to Fillide again. She was his whore. But she was also Rome’s whore, beautiful and violent, dirty at times, at other times shining, glossy with massage and oils. Her face had forced itself into Caravaggio’s mind, then his paintings: his Madonna, his St Catherine, his Judith cutting off the head of her lover Holofernes. Placid in paint; calmly, rigidly beautiful on canvas.

On the street, a whore. Leaving the notables and the rich, Fillide slid at night into the bar brawls, the street fights. She could use a knife, was a match for anyone. Caravaggio was alternately stimulated and awed by her. She made a mouse of him, then a bull. She was uncontrollable, capricious, a liar without remorse, afraid of nothing.

Oh, but she was, and Caravaggio knew it. Knew that she heard the seasons passing, and with them the terrifying power of her appeal. She would age. The fights, the drinking, the whoring – all would age her. If she lived to be thirty, Fillide Melandroni would die foul.

Caravaggio studied her, pausing in front of the canvas and his image of Fillide: his idol, his vicious muse. All of Rome had come to see his paintings, and her. They gazed at the woman who aped a saint, pretending goodness where there was none. As he watched, a fly settled on her left leg, throwing its skeleton shadow on her damp skin, the window open to an airless day.

And as Caravaggio worked on, Fillide thought back to the previous night. She had enjoyed two men and woke smelling of them. Idly, she had scratched herself, then rubbed a cloth over her dirty teeth and counted out the money which had been left for her. Her nails had been blackened, her palms soiled, a cut on her wrist reminding her of a fight with another prostitute. Lazy and still drunk, Fillide had then laid her head on her arms and fallen asleep again.

The afternoon had droned on, sidled into evening, before she finally stirred. Knowing he would send her away if she was dirty, Fillide had washed herself and dressed with resentful attention, leaving her home as the sun had begun to slide into setting.

He had been waiting for her and pulled her into the studio angrily, slamming the door. Without speaking, Caravaggio – the most notorious, aggressive and talented artist in Rome – arranged Fillide on a raised dais. As he handed her a sprig of jasmine she held his gaze. Past lover, present employer, sometime friend. But not today. Today he was giving her jasmine, the white flower of debauchery. He was painting a whore for all to see.

Stifling a yawn, Fillide stirred, allowing Caravaggio to rearrange her pose, lifting the third finger of her left hand. It had been broken in a brawl, Fillide drunk and fighting over money in the alley beside the Piazza Cipriani. When he pushed her head to one side she said nothing, just kept her position, her lips slightly parted.

Satisfied, Caravaggio stood back. It would be a simple painting, a portrait, one of the few female portraits he would ever create. But he knew that Fillide’s beauty, and that undercurrent of sordid promise, would entice. He would sell it easily, poor men slavering over the portrait of Rome’s famous capricious courtesan, rich men gloating over what they had enjoyed.

“Look at me.”

She turned her gaze back to him, her hand cupping the jasmine, the scent lush in the night air. Around them banks of candles burned in rows, giving the artist the glowing illumination and the glowering shadows for which he was known. The smell of wax, the smoulder of the flames and the familiar odour of linseed oil began to build as the night wore on. Their wicks burned down, candles moist in their acrid wax spluttered and were replaced. Other candles smoked, sending up sooty trails, while yet others flickered and sank like falling, burning men.

They did not speak. She was awake but drowsing, held in her pose. He was absorbed, intent, bringing her likeness out of the brown ground of the canvas. Neither of them realised what route the painting would follow, from sixteenth-century Rome to twentieth-century Berlin. Across palazzos and smuggled through Europe. Hidden for a while, relished then idolised, the jasmine still as white and luminous as Fillide’s skin.

*

They didn’t know about the journey which would take the image from a drowsy Roman summer to the brutality of the Second World War. They didn’t know that the image of the Italian whore would survive the centuries, and indirectly cause the murder of six people.

THE THEFT Sicily, 1969

Fillide Melandroni’s portrait would not be the only one of Caravaggio’s paintings to travel. One late October night in 1969, in the Church of San Lorenzo, Palermo, The Nativity with St Francis and St Lawrence was stolen. It was believed that two thieves cut it down from its place over the altar using razor blades. The robbery was a bungled attempt – or so history has it.

The Nativity with St Francis and St Lawrence stands at No. 1 on the FBI’s Missing Works of Art list, the sacred cow of the art world that has had people chasing their tails for decades. Rumours are legion about collectors hiring someone to investigate the picture’s whereabouts. A month or a year later, the result is always the same. Nothing.

But then an unexpected and remarkable solution to the mystery presented itself. In 1996, at a trial in Italy, a Mafia informer, Marino Mannoia, claimed that he had stolen the picture in 1969. With the help of other men he had used a knife to cut the painting out of its frame over the Main Altar of the Oratory of San Lorenzo, Palermo, then rolled it up. Unfortunately, in doing so, the canvas had been ruined.

When the anonymous man for whom he had stolen the work saw the masterpiece, he had wept.

‘It made him cry,’ Marino Mannoia explained. ‘It was not… in a usable condition any more.’

Some doubted Mannoia’s story, but he was considered a reliable witness and had no reason to lie. Besides, it fitted nicely with the theory that The Nativity had been stolen by the Sicilian Mafia. For some, the mystery was solved. Others believed that the painting had met another end. Some adopted the rumour that amateurs had stolen the work and, finding it too notorious to sell on, had had to destroy it. Whichever theory a person favoured, the painting still remained lost.

But there were a number of dealers, collectors, conspiracy theorists and optimists who believed that one of Caravaggio’s greatest masterpieces was still out there somewhere, hidden away. Maybe in Italy, maybe in the Far East, maybe in someone’s bank vault. But not destroyed.

If the work came on to the market now, in the twenty-first century, a conservative estimate of its value would be £60,000,000. Naturally that would depend on its condition. There has been another longstanding rumour that the painting was stolen by amateurs and then dumped in a farm shed and destroyed by pigs. No one knows the truth.

But the enigma of The Nativity with St Francis and St Lawrence remains. Two Caravaggio paintings – one a massive altarpiece, the other a small portrait – worth in excess of £64,000,000 are missing.

*

Or are they? And what if someone should find them? What would a man do for such wealth? What would he be willing to risk?

THE FOOL Berlin, 2014

Luca Meriss was using straighteners, because he hated the way his hair crinkled up. He liked it to look groomed, not like coarse peasant hair. Still, he thought with pleasure, it was a luscious head of hair for a man of over forty. Leaning towards the mirror Luca then studied his teeth, checking there was no plaque, no irritating reminder of a rushed lunch.