‘They think that all we do down here all day is sit on our arses and read the paper,’ Gambetta moaned, grabbing hold of a small set of steps and wheeling them ahead of him, one of the wheels juddering noisily on the concrete. ‘They forget that we have to check every piece of evidence in, and every piece out.’

‘Mmm.’ Allegra nodded, wondering how on earth he managed to bend down to tie his shoes every day, until she realised that he was wearing slip-ons. Not that that accounted for his socks.

‘Most of the time they barely know what the people in their own teams are doing, let alone the other units,’ he called back excitedly over his shoulder. ‘That’s why they missed it.’

The neon tube above where he had stopped was failing, the light stuttering on and off with a loud buzzing noise, creating a strange strobing effect. Climbing up the steps, he retrieved a box that Allegra could see was marked Cavalli and dated the fifteenth of March.

‘It’s the Ricci and Argento cases I’m interested in,’ she reminded him impatiently, but he had already placed the box on the top step and ripped the seal off.

‘Three murders in three days. They may have me stuck down here in the dark with the rats and the boiler, but I’m not stupid.’ He tapped the side of his head with a grin.

‘Three murders?’ She frowned.

‘I left the details on Gallo’s answer machine: Luca Cavalli. A lawyer from Melfi they found hanging from the Ponte Sant’ Angelo with this in one of his pockets -’

He reached into the box and handed her a clear evidence bag. It contained a small lead disc, the plastic slippery against its dull surface as if it had been coated with a thin layer of oil. And engraved on one side, just about visible in the flickering light, was the outline of two snakes and a clenched fist.

J. Edgar Hoover Building, FBI headquarters, Washington DC

18th March – 10.31 a.m.

Tom had given them half an hour or so before making his move. Long enough for Ortiz, Stokes and whoever else had been lurking on the other side of the two-way mirror to have dispersed, but not so long for them to feel the need to check up on him again.

Stepping quickly to the door he flashed Jennifer’s pass through the reader. The device beeped, its light flashing from red to green as the magnetic seal was released. The FBI was good at many things but, as he had suspected, operational efficiency wasn’t one of them. News of Jennifer’s death would still barely have reached the Bureau’s higher grades, let alone filtered down to the foot soldiers who manned the IT and security systems. That gave him a small window of opportunity that would last until someone joined the dots and triggered whatever protocol disabled her access rights and log-ons.

Tom found himself momentarily clinging to this thought. In a way, it was almost as if she wasn’t really dead yet, kept alive instead in a sort of digital limbo. Not that it would last, he realised with a heavy heart. Soon a remorseless and faceless bureaucracy would see to it that the delicate electronic threads to Jennifer’s life were severed. One by one, bank accounts, driver’s licence, social security number, email addresses would all lapse or be cancelled, each heavy keystroke and deleted file wiping a little more of her from the world, until all that would remain were his fading memories.

Swallowing hard and trying to clear his head, Tom ripped the fire evacuation instructions off the back of the door and stepped out into a white corridor. Not wanting to appear lost amidst the thin trickle of people making their way along it, he immediately turned to his right and followed the arrows on the map at the top of the laminated sheet towards what looked like the main fire escape stairwell.

Just before he reached it, however, he came across an open doorway. Glancing inside, he could see that it appeared to be some sort of storeroom – a photocopier idling in the corner, pens, paper and envelopes carefully sorted by type and size stacked on the shelves. More promising was the blue FBI jacket that someone had left hanging over the back of a chair and the internal phone screwed to the wall. Darting inside he slipped the jacket on as a rudimentary disguise, then dialled the operator.

‘I’m trying to find Jennifer Browne’s office,’ He explained when the call was answered. ‘She’s normally based in New York with the Art Crime Team, but she’s been spending some time here lately. I wanted to swing by and surprise her.’

‘Let’s see,’ the voice came back, her fingernails tap-dancing noisily on her keyboard in the background. ‘Browne, Jennifer. Oh yeah, she’s got her calls diverting to Phil Tucker’s office up on five while he’s on leave.’

Memorising the room number, Tom slipped back out into the corridor and headed for the stairwell. He knew that this was a long-shot, that the odds of him getting out of this building undetected and with what he needed were slim. But he’d rather take his chances out here, where he at least had some say in the outcome, than sit in a dark room while Jennifer’s killer slipped even further over the horizon. He owed her that at least. He wouldn’t allow her to fade away.

Clearing the call, the operator immediately dialled another extension.

‘Yes, good morning, sir, it’s the switchboard. I’m sorry to bother you, but you asked that we should let you know if anyone asked for the location of Special Agent Browne’s office. Well, someone just did.’

Headquarters of the Guarda di Finanza, Viale XXI Aprile, Rome

18th March – 4.36 p.m.

‘When was this?’ Allegra asked, returning the bag containing the lead disc with a puzzled frown.

‘The fifteenth,’ Gambetta replied, placing it carefully back in the box.

‘The fifteenth?’ she shot back incredulously. ‘He died on the fifteenth of March? Are you sure?’

‘That’s what it said in the case file,’ he confirmed, looking startled by her reaction. ‘Why?’

The fifteenth was the Ides of March, the same day that Caesar had been killed over two thousand years before. Cavalli and Ricci’s murders weren’t just linked by the lead disc. They were echoes of each other.

‘What was he doing in Rome?’ she asked, ignoring his question.

‘He owned a place over in Travestere. Was probably up and down here on business.’

‘Who found him?’

‘River police on a routine patrol. He was hanging from one of the statues on the bridge – the Angel with the Cross, from what I can remember. Their first thought was that it was a suicide, until some bright spark pointed out that his wrists were tied behind his back. Not to mention that the rope would have decapitated him if he’d jumped from that height.’

‘You mean he was deliberately lowered into the water?’ Allegra asked in a sceptical tone.

‘The current there is quite strong. Whoever killed him clearly wanted to draw it out. Make sure he suffered.’

She detected the same hint of horrified fascination in Gambetta’s voice that she’d noticed in herself when she’d first caught sight of Ricci’s body.

‘Why’s the GDF involved? It sounds more like one for the local Questura.’

‘It was, until they impounded his Maserati near the Due Ponti metro and found fifty thousand euro in counterfeit notes lining the spare wheel. Anything to do with currency fraud gets referred here.’

She nodded slowly, her excitement at this unexpected breakthrough tempered by the depressing thought that this was probably going to make an already difficult case even more complicated. Something of her concern must have shown in her face because Gambetta fixed her with a worried look.

‘Is everything okay? I hope I haven’t…’

‘You did the right thing,’ she reassured him. ‘I’m sure Colonel Gallo will want to come down here in person to thank you.’