As the thunder rolled away, the body fell back with a splash. Madeleine listened carefully, and shuffled forward, balancing on the balls of her feet. When she reached the agent, she leaned down and felt for signs of life. There were none, and Petrovitch crept up beside her.

He knew there was some sort of secret Vatican sign language for times like this, but he didn’t know any of it. Instead, he held up a finger, four fingers, made a zero with his index finger and thumb, then pointed down the tunnel. He meant one hundred and forty meters to the vault. She nodded to show she understood, but he had no idea if he’d actually given the correct message.

The tunnel was relatively straight, but there was no sign of another heat source. Valentina could have fortuitously dropped the tunnel roof on someone, or isolated them on the other side of the rock fall. The niche in the wall that held the ladder up to the surface seemed blank.

Assuming five agents to start with, they’d killed one, and neutralized another. One would be left in the short tunnel to the under-tower shaft—to help lower that heavy bomb down—and two to enter the vault and set the bomb.

He wondered what they were waiting for. They had to have the bomb in place by now, and every second that passed was a second less on the countdown. He’d had enough of creeping along: he stood up straight, and started shambling toward the gaping cold hole in the brick, making no pretense at stealth.

He pressed his back against the crumbling wall and patted his pockets. Nothing there. He’d used the stun grenades already, and he didn’t think Madeleine had any left either. He’d have to improvise.

“Hey, Yankee,” he called, and flinched as a hail of bullets hammered the far side of the tunnel. The soft brick absorbed the impacts, cracking and spalling. The air filled with dust, but save for a few larger fragments of baked clay, he wasn’t struck. The firing stopped, the muzzle flashes flickering away like lightning.

Madeleine came up next to him. He couldn’t see her eyes, hidden behind the green lenses of her night sights, but he could tell she was appalled at his recklessness. He grinned in the dark.

“Hey,” he started, and held up his good hand to his face to protect it from yet more shrapnel. “Yobany stos, will you stop that?” He waited for a pause, and tucked his gun in his waistband again.

“What are you doing?” Madeleine hissed.

“Making it up as I go along.” He unhooked a sphere from his arm, and primed it. The little green light winked on. “You seen what my singularity bombs do yet? I have. I’ve seen what they can do to a car. I’m just wondering how much of you there’s going to be left to ship back home. I’ve some airmail envelopes around somewhere. Should be big enough.”

Madeleine had ducked down and hidden beneath the lip of the hole, swapping the shotgun for her Vatican special. Petrovitch threw the singularity device through the hole, against the side of the tunnel wall. It bounced out of sight, and started to roll downhill.

There was another storm of noise and light, but this time the bullets weren’t directed out at them. They were aimed at the trundling sphere, picking up speed as it rattled and clattered toward the shaft, a spinning green light marking its passage.

Madeleine pushed the pistol above her head and emptied the entire magazine blind, pointing it at all angles into the space beyond.

The air tasted of spent powder and dirt as the final shell case fell with a clink.

“Yes or no?” asked Petrovitch.

Madeleine swapped her empty magazine for a full one. “I’ll find out.” She dislodged a loose brick from the top of the ragged wall and let it fall at her feet. She retrieved it, and lobbed it inside. No returning fire.

“Yeah, we haven’t got time for this.” He pulled his automatic and backed up to the far side of the river culvert, edging up the curve of the wall until he could see down the length of the tunnel all the way to the shaft.

There was a splash of color at the far end, all hot whites and yellows. It showed what looked like a leg, maybe a hand reaching out for the bright-painted stick that could only be a rifle. Petrovitch drew crosshairs on the main mass and fired three times.

Madeleine leaped up and over the wall. The mortally injured man was bundled out, suspended for a moment across the top of the brickwork before toppling into the river.

Petrovitch splashed toward him, then along and over him, using his shoulders and head for purchase to gain enough height. Madeleine reached over and pulled him in.

“You know this is just madness, don’t you?” she told him as he crashed to the floor.

“We’re trying to prevent a bunch of fanatics armed with an atomic bomb from putting a glowing crater in the Freezone. Compared with what we’ve already been through, this counts as sane.” He held his good hand up. “Shall we do it, then? Take revenge for all the ones the Armageddonists got through?”

Her fingers tightened around his wrist and he was dragged upright. “That’s what everyone wants, isn’t it? In their nuclear dreams, they get to stop them, just once.”

She pushed her night-vision goggles up her forehead long enough to kiss him hard on the lips. Then she pushed him behind her, and knelt down to crawl toward the sharp-edged void of the shaft.

32

The singularity bomb was shattered: the resin that had held the warp and weft of the wire had been reduced to a few large fragments with the rest of it turned to pea-sized grit. That meant he had two left, then. Petrovitch and Madeleine sat on opposite sides of the end of the tunnel and looked out over the shaft.

Madeleine checked the rope, which had been tied around the base of the last tunnel support.

“I still don’t get what’s keeping them.” Petrovitch curled his fingers around the haft of a shovel and felt its reassuring, primitive weight. “If it had been me, I’d have blown it by now. There has to be a good reason.”

“And you want to exploit it.”

“We’re not dead yet.” He peered over the edge; no mines or tripwires that he could see. He glanced upward again, at the great mass of debris hanging high above their heads.

“If I lower you down, both of us are vulnerable at that point. If they’re watching the shaft…” Madeleine studied the vault doors. The stone that had kept them ajar had been kicked aside, and it rested almost shut on the thickness of a fiber-optic cable.

“I need to get down there,” he insisted.

“You really think you’re going to talk them out of this?”

“I think I should try. It’s not over till the Fat Boy sings.”

“Sam, I want you to listen to me.” She dragged his face around. “They’re not going to be dissuaded. They’re not just soldiers, they’re martyrs. I understand this sort of thing. They’re not going to recant; they believe in what they’re doing.”

“I don’t.”

“You can’t stop them. We can’t storm the vault, and they won’t come out. They’re in there and, whatever it is they’re waiting for, anything you say is more likely to make them detonate early, not less.” She took the shovel from him and put it to one side. She clasped his now-empty hand in both of her own. “I want a future with you. I don’t know where it’s going to be or what it is we’re going to be doing, but I want it with you. That’s never going to happen if we stay here.”

“Ireland,” he mumbled. “We’re supposed to be going to Ireland, set up a Freezone on a long contract. We’re citizens—diplomats, even. It’s all arranged, everything. Michael is there already; the Irish government in exile have installed a quantum computer in the Cork mission station. That’s what we were going to do.”

“Then why are we sitting in a cold dark tunnel under the center of what used to be London, trying to protect something that is no longer of any importance, trying to persuade some zealots not to blow themselves up?”