As she walked it started to spit with rain, the sky huddling beneath a thick blanket of grey clouds, as if it didn’t want to be woken. The Pantheon loomed ahead of her, the classical elegance of the three rows of monolithic granite columns which supported its front portico compromised by the hulking, barrel-shaped building behind it. Squat and solid, it appeared to sit in a small crater of its own invention, the streets encircling it as if it had fallen, meteor-like, from the sky, and buried itself between the neighbouring buildings.

Allegra walked up to the portico, stooping under the police tape that had been strung between the columns, and made her way inside the rotunda, her shoes squeaking on the ancient marble. Almost immediately she paused, her eyes drawn to the pale beam formed by the searchlight of the helicopter hovering overhead as it was funnelled through the circular opening at the apex of the coffered dome. A slanting column of light had formed between the ceiling and the altar, sparks of rain fluttering around it like fireflies trapped in a glass jar. It was a beautiful and unexpected sight.

‘Are you coming in, or just going to stand there like a retard?’ Salvatore crossed through the beam of light, sounding even more put upon than he had yesterday.

‘“Hello” would be nice.’

‘You’re late.’

‘Believe me, it takes years of practice to be this unreliable.’

‘Gallo’s not happy.’

‘He doesn’t exactly strike me as the happy type.’

He eyed her unblinkingly, looking both appalled and yet also slightly envious of her brazen tone. He gave a resigned shrug.

‘Suit yourself.’

There were about fifteen, maybe even twenty people inside, some in uniform interrogating the security guards who’d been covering the night shift, others in hooded white evidence suits taking photographs or examining the floor around the altar, which itself was obscured by some makeshift screens. Gallo, in a suit this time, was waiting for her next to Raphael’s tomb, his hands folded behind his back like a teacher readying himself to hand out a punishment. As Salvatore had warned her, he was in a dark mood, and she found herself wondering if the angry atmosphere she’d noticed on the other side of the barricades was in some strange way linked to his own emotional barometer.

‘Nice of you to show up.’

‘Nice of you to ask me.’

Gallo paused, lips pursed, as if he couldn’t quite decide if he found her insolent or amusing.

‘Where did you say you were from?’ he asked, taking his glasses off and polishing them on his tie.

‘I didn’t. But it’s Naples,’ she stuttered, his question taking her by surprise.

‘An only child?’ It was a simple question, but she could tell from his tone that it was loaded with meaning – difficult, spoilt, selfish, stubborn. Pick your stereotype.

‘That’s none of your business.’

He paused again, then gave an apologetic nod.

‘You’re right. I’m sorry.’ Salvatore made a strangled noise next to her. She wondered if this was the first time he’d ever heard Gallo apologise.

‘You say what you think, don’t you?’

‘Pretty much.’

‘The difference between you and me is that you can get away with it because you’re a woman,’ Gallo sniffed. ‘When I do it, I get called a rude bastard.’

‘I wouldn’t say you were rude, sir.’ The words were out of her mouth before she even knew she was saying them.

His smile faded. Salvatore looked faint.

‘What can you tell me about this place?’ he snapped, motioning at her to follow him over to the altar.

‘What do you mean?’

‘The Pantheon. Is there anything I should know about it? Anything that might tie it to where we found Ricci’s body last night?’

She ran her hand through her hair, desperately trying to dredge up the highlights of some longforgotten lecture or text book.

‘It was built by Hadrian in about 125 AD, so there’s no obvious connection to Caesar, if that’s what you mean?’ she began with a shrug. ‘Then again, although it’s been a church since the seventh century, the Pantheon did used to be a pagan temple, just like the ones in the Area Sacra.’

‘Hardly conclusive,’ Gallo sniffed, patting his jacket down as if he was looking for cigarettes and eventually finding a packet of boiled sweets. ‘I’m trying to give up,’ he admitted as he popped one into his mouth. She noticed that he didn’t offer her one.

‘No,’ she agreed with a firm shake of her head.

‘Then what do you make of this?’

At a flick of his wrist, two forensic officers rolled away the screens. A body was lying on the altar, naked from the waist up. His bearded face was turned towards them, eyes gaping open with shock. Two gleaming white shop mannequins were standing at his head – one small and hunched, the other taller – staring down at the corpse with cold, vacant expressions. Both were unclothed, with moulded blank features and no hair, although the smooth hump of their breasts marked them out as female.

The taller mannequin had been carefully arranged so that her left hand was gripping the man’s hair and the right holding a short sword. The sword itself was embedded in a deep gash in the victim’s neck that had almost decapitated him. The blood had gushed from his wound, covering the altar and cascading to the floor where it had pooled and solidified into a brackish lake.

It was a carefully arranged, almost ritualistic scene. And one that, for a reason Allegra couldn’t quite put her finger on, seemed strangely familiar to her.

‘Who is it?’

‘Don’t you recognise him?’ Salvatore, looking surprised, had ventured forward to her side. ‘His brother’s always on TV. He looks just like him.’

‘Why, who’s his brother?’ she asked, wanting to look away and study the man’s tortured features at the same time.

‘Annibale Argento,’ Salvatore explained. ‘The Sicilian deputy. The stiff is his twin brother Gio, otherwise known as Giulio.’

‘Hannibal and Julius,’ Gallo nodded. ‘There’s your damn Caesar connection.’

‘What’s any of this got to do with me?’ she interrupted, wondering if she still had time to untangle herself from this mess before the media got wind of it.

‘We found this in his mouth -’

Gallo held up a clear plastic evidence bag. She knew, almost without looking, what it contained.

Amalfi Hotel and Casino, Las Vegas

17th March – 11.02 p.m.

Kezman’s private elevator opened on to a tennis court-sized room, rainbows cloaking the lush tropical gardens that could be glimpsed through the open windows where the floodlights shimmered through a permanent cooling mist.

Glancing up, Tom could see that the soaring ceilings had been draped in what looked like black satin, three huge chandeliers flowering from within their luxuriant folds as if they were leaking glass. The only furniture, if you could call it that, was a 1926 Hispano-Suiza H6. Parked about twothirds of the way down, it was a mass of gleaming chrome and polished black metal, the wheel arches soaring up over the front wheels and then swooping gracefully down towards the running boards, two dinner plate-sized headlights perched at the end of a massive bonnet like dragon’s eyes.

‘You’re here. Good.’

A man had come in off the balcony, a radio in one hand, a mobile phone in the other. Short and wiry, his olive skin was pockmarked by acne scars, his black hair shaved almost to his skull. Rather than blink, he seemed to grimace every few seconds, his face scrunching into a pained squint as if he had something in his eye.

‘Tom, this is Special Agent Carlos Ortiz.’ They shook hands as she introduced them. ‘I’ve borrowed him from my other case for a few days to help out.’

‘Welcome.’

Ortiz’s expression was impenetrable, although Tom thought he glimpsed a tattoo just under his collar – the number fourteen in Roman numerals. Tom recognised it as a reference to the letter ‘N’, the fourteenth letter of the alphabet, and by repute to the Norteños, a coalition of Latino gangs from Northern California. Ortiz had clearly taken a difficult and rarely trodden path from the violent street corners of his youth to the FBI’s stiff-collared embrace.