There was a sudden, unexpected noise behind them. Something coming out of Emily Deacon’s jacket and not a phone this time, a pop, like the report of a small gun, and she was screaming again, terrified to move, terrified to stay still. A bright spark, alive and fiery, was worming its way out of the uppermost yellow canister on the vest.

The men were scattering again. Costa took a good look at the jacket, walked over, tried to hold her still, wrapped a handkerchief around his fist and jabbed at the burning object. It came out, stinging his fingers. He threw it to the floor, where it fizzled ominously.

“Don’t play games,” Costa barked at the phone. “She didn’t deserve that.”

You don’t know what you deserve!” Kaspar yelled back. “You don’t have a clue.”

Costa wasn’t listening. He was back with Emily, hand to her head, noting the tears in her eyes, the look of terror there.

“I’m sorry,” she gasped. “I’m so sorry.”

Kaspar’s laugh rattled out of the phone. “Good! Are you people learning something here? Improvisation’s everything. A man needs tricks up his sleeve. What you got there was the demo. A little firecracker to keep you on your toes, folks. Still leaves me with seven real ones, though. Plus the set I got here, somewhere you’d never guess, full of lots of people who surely wouldn’t want to die without knowing what Christmas presents they’ve got. Ask your munitions moron to stick his nose round Little Em’s vest. This is real, people. Don’t ever forget that.”

“This is real,” Emily Deacon murmured to no one, head down.

Viale, Leapman and the two Americans were slinking back to the centre of the hall now, looking somewhat ashamed.

Costa scowled at them, picked up the phone, turned off the speaker and held the handset to his ear, ignoring Leapman’s protests. “My name’s Nic Costa. Rome police. Tell me what you want, Kaspar, and I’ll tell you if they can give it to you.”

A pause on the end of the line. A wry, amused laugh, and Costa knew somehow: he was dealing with someone very smart. “Finally. Mr. Costa. Are we talking privately, son?”

The voice in his ear had changed. The person behind it sounded closer. More human. And just a little apprehensive too.

“Yes,” Costa replied and listened, very carefully, as he watched Gianni Peroni restrain the furious Leapman from grabbing the phone.

I like that. So you think you can convince them to let you out of that place with something?”

“Yes,” Costa said, and tried to sound convincing.

Good. I’m impressed.”

“Meaning?”

That laugh again. “Meaning we’re halfway there already. ”Cos I got something for you.“

Then the line went dead. Nothing, not a single background noise, a half-heard word from a third party, gave Costa a clue about where Kaspar was really located.

Leapman was shaking with fury. Peroni released him. The American pointed at Falcone and spat, “That was not part of the deal!”

“You were losing it,” Falcone said coldly. “If you’d gone much further she’d be dead, and the rest of us too, probably. Save your thanks for later.”

“You-”

“Shut up! Shut up!” Emily Deacon looked ready to break. She was hugging herself inside the deadly parka, gently rocking backwards and forwards, tears streaming down her cheeks.

“For God’s sake,” she pleaded, “either give him what he wants, or just get the hell out of here so he doesn’t kill the rest of you too.”

To Costa’s amazement, that did, at least, give the FBI man pause for thought.

“What does he want?” Leapman demanded.

“Just what he asked for last night,” Costa explained quietly. “Proof.”

“Great,” Leapman grunted. “And in return?”

Costa phrased this very carefully. “In return, he swears he’ll give himself up. He’ll take off the vests, disarm them both-”

“What?” Viale looked livid. “We’re supposed to take that on trust? I want him in my sight before he gets a damn thing. I’m not waiting on a promise.”

Costa caught Emily’s eye. He wanted her to know there was still hope, still room to make things right. “I guess he’s thinking much the same way. He wants me to take him the evidence you’ve got. He’ll check it out. If it’s real. Then-”

“Where’s the delivery?” Falcone asked.

“I don’t know,” Costa lied. “He said he’d phone along the way. And don’t try to follow me. If he sees that, sees anything that suggests we’re trying to trick him, it’s all over.”

Costa watched them turn this over in their heads. He knew what defeat looked like.

“He’s set this up so we don’t have a lot of choices,” he argued. “He’s not stupid enough to walk in here to collect. I don’t think we’re in a position to get round him either. Do you?”

Leapman stared at the stone floor in despair. “Jesus,” he moaned. “The bastard’s still running rings around us.”

Costa risked a hopeful glance in Emily’s direction. “Let me do it,” he urged. “What’s there to lose? He’s adamant. If he gets the documents you promised, he comes back with me and he’s all yours. He said he’d ”surrender.“ That was the word he used.”

A military word, Costa thought. One that would strike a chord with a man like Joel Leapman.

“Do we have any other options?” Falcone wondered. “Is any part of this negotiable?”

Costa shook his head. “Absolutely not. I wouldn’t even know how to phone him back. He blocked the number.”

“Bill Kaspar,” Leapman sighed. “What a guy.” He looked Costa straight in the face. “This place is a church or something, right?”

“Among other things.”

“Really.”

Leapman walked over to Viale, held out his hand, then, when the SISDE officer didn’t move an inch, took the blue folder from under his arm.

“This is mine,” Leapman said, handing him the thing. “I read it on the way here. There’s no one in there but Dan Deacon. If that doesn’t convince him Deacon was to blame, then nothing will. You go run your errand, Costa. We stay here and pray.”

THE SKY WAS HAVING second thoughts. It was still bright, but there was a hint of hazy ice seeping into the blue. More snow, Costa thought. Not for a few hours, but it was on the way, a final random throw of the dice for this extraordinary Christmas.

He walked out of the shadow of the Pantheon doors, waited as Peroni closed the vast bronze slab behind him, then strode down the steps into the piazza, close to where Mauro Sandri had fallen three nights before. So much in such a short space of time. This must have been what it was like for Kaspar in Iraq. Constant movement, constant threats. That experience shaped the man now, made him what he was. Obsessed with detail and planning, tied to the symmetry of the complex web he’d spun around all of them, weaving his way through its intricacies with an extraordinary, lethal dexterity.

Teresa Lupo sat outside a cafe. She looked at him and tugged her thick coat around her, then sipped at a cup of something that steamed in the cold, dry air.

Costa stopped by her table and scanned the square. It was almost deserted.

“Did it work?” she asked.

“I believe it did,” he answered. “And one day you’re going to have to tell me how.”

“Just some predictable pleas and threats.” She sighed. “I’m not really cut out for this, Nic.”

Just for a moment he smiled. “You could have fooled me. Here.” He threw the file on the table. “Keep it safe.”

She glanced at the folder, opened it, flicked through the sheaf of papers, each with the SISDE log on top, each marked “secret.”

“Oh my,” she said softly. “Are we in deep now?”

“Keep the faith,” Costa said and walked on, to the far side of the square, and waited a good two minutes.

Then the phone rang and he heard Kaspar’s now familiar voice.

You got good people, Costa. I like this. So where are you going?”

“Piazza Sant” Ignazio,“ Costa said.