Even as this thought occurred to him, he felt Jennifer’s image forming in his mind. An image he’d tried to suppress ever since he’d seen the gurney disappear into the bowels of the hospital, and then been escorted back on to Kezman’s jet and flown to this windowless interview room. But there she was, bloodied, her face shrouded by an oxygen mask, arms pierced by wires. A martyr? A sacrifice? But if so, for what and by whom?

‘If we’re going to catch the people who did this, we’re going to need your help.’ Ortiz, standing to his right, had adopted a more conciliatory tone which Tom sensed was genuine, rather than some clumsy attempt at a good cop, bad cop routine. His cheeks were shadowed by stubble, his eyes tired.

‘You’re not going to catch anyone, stuck down here,’ Tom retorted. ‘The longer we talk, the colder the trail. We should be in Vegas.’

‘SOP says we pull back and let an IA team step in when an agent falls in the line of duty,’ Stokes intoned, sounding as though he was reciting from some sort of manual. ‘They’re on the ground there already, reporting directly to FBI Director Green.’

‘To FBI Director Green?’ Tom asked, momentarily encouraged. He knew Jack Green, or at least had met him a few times when working with Jennifer. He had first-hand experience of the help Tom had given the Bureau in the past. ‘I want to talk to him. Does he know I’m here?’

Ortiz’s eyes flickered questioningly towards the large mirror that took up most of the left-hand wall. Tom’s heart sank. Not only did Green know he was here, but, judging from the uncomfortable expression on Ortiz’s face, he was probably watching. Jennifer’s death had clearly reset the clock. Until they knew exactly what had happened, he wasn’t going to qualify for any special treatment.

‘You can talk to us instead,’ Stokes snapped. ‘Tell us what happened.’

‘You know what happened. You were there. You saw the whole damn thing.’

‘All I know is that twelve hours after Browne brought you into the case, she was dead.’

‘You think I had something to do with it?’ Tom’s anger was momentarily overwhelmed by incredulity.

‘Twenty million dollars is a lot of money.’ Stokes’s eyes narrowed accusingly. ‘Even for you.’

‘So that’s your theory? That this was some sort of botched heist?’ Tom wasn’t sure whether Stokes was being deliberately provocative, or just plain stupid.

‘I think that shooting a federal agent is a pretty good diversion. If one of our agents hadn’t secured the suitcases, who’s to say -’

‘If all they’d wanted was a diversion, they could have shot anyone in that place,’ Tom countered. ‘They could have shot me.’

‘Exactly.’ Stokes raised his eyebrows pointedly, as if Tom had somehow proved his point.

‘Except they didn’t. They chose Jennifer. Maybe you should be asking yourselves why,’ Tom insisted.

‘What are you talking about?’ Stokes said with an impatient shrug.

‘Jennifer told me that two weeks ago she’d stumbled across an antiquities smuggling ring,’ Tom said, looking to Ortiz who acknowledged this point with a nod. ‘Then, out of the blue, a longlost Caravaggio shows up. One of the few works in the world guaranteed to ensure that Jennifer gets the call. You think that’s a coincidence?’

‘You don’t?’ Ortiz asked him with a frown.

‘I did until last night.’ Tom shrugged. ‘But now I’m thinking that there never was any Caravaggio; never was any exchange. That it was all a set-up. That that’s why the priest started stalling. Because he was expecting Jennifer. Because he wanted to give the gunman enough time to find her.’

‘This was about the money, and you know it,’ Stokes said with a dismissive wave of his hand. ‘We just got to it before you or anyone else could.’

‘Jennifer told me that the dealer you arrested in Queens had given you a name. Someone in Italy,’ Tom said to Ortiz, still ignoring Stokes. ‘Who was he? Did he have any ties to the mafia?’

‘Why? What do you…?’

‘That’s classified,’ Stokes interrupted angrily before Ortiz could answer. ‘Browne trusted you with too much, and you shouldn’t be encouraging him.’ He jabbed his finger at Ortiz.

‘The mafia control the illegal antiquities business in Italy,’ Tom explained. ‘They decide who can dig where, and take a cut on everything that comes out of the ground. It’s worth millions to them. The same mafia who, if you believe the rumours, have been holding the Caravaggio all these years.’

‘What are you saying?’ Ortiz breathed, ignoring Stokes’s venomous gaze.

‘I’m saying it was a professional hit. I’m saying that something she’d stumbled across had made her a threat and that the painting was just a way of flushing her out into the open.’

‘If you’re right…’ Ortiz said slowly.

‘If I’m right, then we’re already too late to catch the killer. You can run a DNA test on the blood traces, but people like that are ghosts. You’ll get nothing. But I might still be able to find whoever ordered the hit.’

‘You might be able to find them?’ Stokes gave a hollow laugh. ‘We’ve got a long way to go yet before we’ll even let you take a piss without someone holding your dick for you.’

‘Let me see her files.’ Tom turned to Ortiz. ‘I can go places you can’t, speak to people you don’t know. But I need to move fast. I need to move now.’

Ortiz went to say something, but then hesitated, his eyes again flickering towards the mirror.

‘Yeah, sure!’ Stokes gave a rasping laugh. ‘Get a load of this guy. Our necks are already on the line and now he wants us to bend over and drop our pants too?’

‘Then either charge me with something, or let me go,’ Tom shouted angrily, rising to his feet. ‘Right now you’re just wasting my time.’

‘Like I said, Kirk, you’re going nowhere,’ Stokes said coldly, standing up and swiping the door open.

‘I’m sorry, man,’ Ortiz shrugged, joining him in the doorway. ‘But he’s right. This is how it’s got to be.’

The door sealed shut behind them and the electronic reader flashed from green to red. Saying nothing, Tom reached into his trouser pocket and felt the hard outline of the swipe card Jennifer had pressed into his hand in the helicopter.

Even then, as she lay dying, she’d known how this would play out. Even then, she’d known what he would have to do.

Ospedale Fatebenefratelli, Isola Tiberina, Rome

18th March – 3.51 p.m.

Allegra had left Aurelio in yet another of his sulks. She had arrived late and was now leaving early, he had complained as she hurriedly saw herself out. She had pointedly reminded him that she was only leaving so she could follow up on a case that he was responsible for her being involved with in the first place. But by then he had turned the radio on and was pretending he couldn’t hear her. No matter. All would be forgiven and forgotten by tomorrow, she knew, his moods breaking and clearing as quickly as a summer storm.

Allegra wasn’t sure whether the link between the lead discs and the Delian League was meaningful or not, but one thing that she was almost certain about was that Gallo would want to know about it ASAP, so he could make that decision for himself. Normally she would have called him, but his phone appeared to have been switched off. According to his assistant, this was because there was no reception in the mortuary basement levels, where she would still catch him if she hurried.

Having signed in, she headed down to the cold store in the basement. A young man wearing a white lab coat – a medical student, she guessed, judging by his age – was manning the reception desk and glaring at a monitor.

‘Colonel Gallo?’ she asked, flicking her wallet open. He jumped up, deftly minimising a game of solitaire.

‘You just missed him,’ he replied anxiously, leaning over the top of the counter and peering down the corridor behind her as if he still might be able to see him. ‘Signor Santos is still here, though.’