‘Is that it?’ Verity breathed over his shoulder, pulling on a pair of white cotton gloves.

‘That’s it.’ Sliding the shallow box out, he carefully placed it on top of one of the neighbouring packing crates. Removing his jacket, he lay it over another crate so that its scarlet lining covered it. Then he gingerly removed the mask and set it on top of the lining, the pale ivory leaping off the red material. Finally he stepped back and ushered her forward.

‘Please.’

Approaching slowly as if she was afraid of waking it, Verity pulled on a pair of white cotton gloves and carefully picked the mask up. She raised it level with her face, eyes unblinking, the colour flushing her throat and cheeks, her breathing quickening, hands trembling. For a moment, it seemed she might kiss it. But instead, she gave a long sigh of pleasure and lowered it unsteadily back into its straw bed, her shoulders shaking.

‘So? What do you think?’ Faulks asked, after giving her a few moments to compose herself.

Verity made to speak, but no sound came out, her lips trembling, tears welling in her eyes. She looked up at him, her hand waving in front of her mouth as if she was trying to summon the words out of herself.

‘It’s so beautiful,’ she breathed eventually. ‘It’s like…it’s like gazing into the eyes of God.’

‘Attribution?’

‘Assuming the dating is right…’

‘Oh, it’s right.’

‘Then Phidias. Phidias, Phidias, Phidias!’ Her voice built to an ecstatic crescendo. ‘We would have heard of any other sculptor from that period of this quality.’

‘Then I hope you won’t mind confirming that to my buyer?’ Faulks pulled out his phone and searched for a number. ‘Or the valuation you’ll put on it once he donates it to you?’

‘Of course,’ she enthused, snatching the phone from him as soon as it started ringing. ‘What’s his name?’

Over Milan, Italy

20th March-6.27 p.m.

Darkness. The smell of straw. A dog barking.

Coming round, Allegra lifted her head and then sank back with a pained cry. There was something above her preventing her from sitting up. Something smooth and flat and…wooden. She moved her hands gingerly across it, sensing first its corners and then the constrictive press of the walls at her side. It was a box. She was lying in a wooden box.

The last thing she remembered was Faulks, wildeyed, raising his umbrella above her like an executioner’s axe and then…darkness. Darkness, the smell of straw, a dog barking, something hard and uneven underneath her, her head throbbing where he’d struck her. And in the background a low, incessant drone, a rushing whistle of air, a bass shudder.

A plane. She was on a plane. Lying in a wooden box in the hold of a plane.

She nervously patted her inner thigh, and then sighed with relief. The location transmitter was still there-taped to her skin at the top of her leg where they only would have found it if they had stripped her down.

She’d taken a big risk, she knew. A risk that Tom would never have agreed to. But as soon as it had become clear that there was nothing in either Faulks’s papers or the safe that was going to give them even the slightest hint as to where the League was meeting that night, she’d known what she had to do. Grab the transmitter and some tape out of the bag. Hold back amid the confusion of their hurried retreat as Faulks pounded along the corridors towards them. And then try to talk or shock him into delivering her to the League himself. It was that or give up on getting to the painting before Santos could hand it over to the Serbs. It was that, or admit that they couldn’t stop him.

‘Stop’ was a euphemism, she knew, for what the Serbs would do to him if he failed to deliver the Caravaggio. The strange thing was that, after the horrors she’d witnessed and endured over the past few days, she felt remarkably sanguine about his likely fate. Especially when the alternative was that, armed with his diplomatic immunity and the proceeds of the Caravaggio’s sale, Santos would escape any more conventional form of justice.

Tom had said that the radius of the transmitter was three miles. No use at thirty thousand feet, but if he’d realised what she was doing when she hadn’t come back down, and then followed her signal to the airport, he should have been able to work out where she was heading and take another flight to the same destination where he would hopefully be able to pick up her signal again when she landed. At least, that was had been her rough, ill-conceived plan.

For now, all she had was darkness and the sound of her own breathing. Its dull echo, in fact, that seemed to be getting louder and louder as the box’s walls closed in, pressed down on her chest, her lungs fighting for air.

Suddenly she was back in the tomb. The entrance blocked, the earth cold and clammy underneath. She called out, her fists pounding against the sides, her feet drumming against the end, twisting her body so that she could lever her back up against the lid.

There. Above her head. Two small, perfectly round holes in the wood that she hadn’t been able to see before. She inched forward on her stomach, pressed her face to them, drinking in the narrow rivulets of air and light with relief, her heart rate slowing.

She looked down, struck by a sensation of being watched.

In the dim light, a pair of lifeless eyes stared back up at her, cold lips parted in a hard smile, nose sliced off.

She was lying on top of a statue. A marble statue. But to Allegra the statue might as well have been a corpse, and the box a coffin, and the rumble of the engines the echo of loose earth being shovelled back into her grave.

Cimitero Acattolico, Rome

20th March-10.22 p.m.

‘I’ve lost her,’ Tom barked.

‘What do you mean, you’ve lost her?’ Archie grabbed the receiver from him and shook it. ‘She was just there.’

‘Well, she isn’t now,’ Tom shot back, his anger betraying his concern.

Until now, Allegra had proved surprisingly easy to track, her signal leading them from the Freeport to the cargo terminal at Geneva airport, where they had observed Faulks’s driver overseeing several large crates being loaded on to a plane bound for Rome. It hadn’t taken much imagination to deduce that she had been placed inside one of them. They had therefore immediately booked themselves on to an earlier flight to ensure that they would already be in position to pick up the signal again by the time her plane landed.

Watching through his binoculars from the airport perimeter fence, Tom had been able to tell that this was a well-established smuggling route for Faulks, the Customs officers welcoming him off the plane on to a remote part of the airfield with a broad smile as a black briefcase had swapped hands.

The cargo had then been split, some heading for the warm glow of the main terminal, the rest to a dark maintenance hangar into which Faulks had driven, the doors quickly rolling shut behind him. Then for two, maybe three hours nothing. Nothing but the steady pulse of her location transmitter on the small screen cradled in his lap. A pulse that had served as a taunting reminder of the fading beat of Jennifer’s heart-rate monitor in the helicopter over the desert. A pulse which they had carefully followed here, only to see it flatline.

Sheltered by regimented lines of mourning cypresses and Mediterranean pines, the Cimitero Acattolico nestled on the slope of the Aventine Hill, in the time-worn shadow of the Pyramid of Caius Cestius and the adjacent Aurelian walls. Even by moonlight, Tom had been able to see that it was populated by an eclectic tangle of stone monuments, graves and family vaults, separated by long grass woven with wild flowers. These elaborate constructions were in stark contrast to the trees’ dark symmetry: pale urns, broken columns, ornate scrollwork and devotional statuary bursting in pale flashes through the gaps in their evenly spaced trunks, as if deliberately planted there in an attempt to prove the superiority of human creativity over natural design.