“Shit!”

The level of illumination plunged. She whirled, seeing the man standing in the open doorway, blocking the light. The gun was a menacing black shape in his hand.

The gun-

She had one of her own!

Nina snapped up the stolen MP9 and yelled a battle cry of pure fury as she hosed the passage with the entire contents of the clip. Spent shell casings pinged off the wall and sizzled past her as she swung the gun back and forth, almost blinded by the muzzle flash.

The hail of fire ceased abruptly as the magazine ran dry. Her shout died as she tried to blink away the wafting afterimages of flame, hoping to see the man lying dead on the floor…

He wasn’t. He wasn’t even in sight. He must have flung himself back into the library just as she started shooting-

The second, nearer library door opened, more light filling the passage. The man stepped through it, gun raised. Through the hole in his black balaclava, his mouth twisted into an unpleasant smile.

“Ooh, out of bullets,” he said in a patronizing tone. “Never mind, I’ve still got plenty.”

“You won’t shoot me,” said Nina, faking defiance. “You need me alive.”

The gun tilted down to aim at her bare legs beneath the long shirt. “You can shoot someone and not kill them, you know.” He advanced on her. “Just give me an excuse-”

There was a discordant squeal from the other end of the passage as something flew through the far door and hit the wall before dropping to the floor. The startled gunman whirled, gun blazing-and blew Mac’s wailing bagpipes to shreds.

He stepped forward. “What the fu-”

The shotgun boomed from the library, blowing the man’s knees to a gruesome pulp. He fell, howling in agony.

Mac hobbled over with a snooker cue wedged under his arm as a makeshift crutch. “Oh, shut up,” he growled at the screaming man, slamming the butt of his shotgun against his head. The noise stopped immediately. “Are you okay?”

“Yeah,” Nina said.

“Get to the stairs. Go!”

She didn’t hesitate this time, running for the far end of the corridor to find another door. To her relief, there were stairs beyond this one. She started to run down them-only to stop at a noise from below. Someone was running up them!

She turned back, reentering the library. “They’ve cut us off!”

Mac muttered a curse. “Onto the landing!”

“But they’ll be coming up the stairs-”

“Come on!” The tip of the cue banging against the floor, he staggered to the door. Nina followed.

Another man was on the landing below. Mac loosed a shotgun blast at him, forcing him to dive back behind a support pillar for cover.

The intact rope still hung from the broken skylight. “Can you climb a rope?” Mac asked, swinging the barrel of his gun to snag it.

“I can hang on to a rope,” Nina said nervously, realizing what he had in mind, “but that’s not the same thing!”

“It’s your only way down! Just get out the front door, and run!” He thrust the black line into her hands, then pumped another round and fired again at the man on the floor below. Plaster spat from the pillar. “Go!”

“Oh, God!” Nina wailed as she gripped the rope as tightly as she could…

And swung out from the landing over empty space.

If she hadn’t trained with Chase, she would have lost her grip. Shirt billowing in the breeze, one slipper falling from her foot, she lowered herself hand over hand as quickly as she dared.

It wasn’t quickly enough. Even as she heard Mac reloading, the man leaned out from behind the pillar and saw her. He jerked his gun towards her, then hesitated, remembering his orders to take her alive. He ducked back as Mac fired again, pellets cratering the walls. “She’s going down on her own!” the man yelled, Nina for the first time seeing the line of a radio microphone curving in front of his mouth.

She increased her pace, dropping faster. Her hands, damp with sweat and fear, started to slip on the rope, friction burning her palms-

“Fire in the hole!” The man, now level with her, swung out of cover to throw something up at Mac’s position.

A grenade-

Mac saw it arc through the air towards him. He turned and dived into the bathroom.

Nina loosened her grip and slid down the rope, barely able to control her descent. Her hands seared. Above, she heard a clack as the grenade landed just outside the bathroom.

Mac dropped his gun and the makeshift crutch, using his one good leg to propel himself over the rim of the bath-

The grenade detonated.

This was no stun grenade, but a lethal explosive.

The balustrade was blasted to pieces, shattered wood spinning through the air into the hall below. The blast ripped through the open door of the bathroom, the window blowing out.

The rope shuddered in Nina’s hands, then went slack, severed. She was still more than ten feet above the unforgiving marble floor, and unprepared for the fall. She plummeted-

And landed on the body of the man Mac had shot in the thighs. The impact knocked the breath from her, her ankle flaring with pain.

Gasping, she looked up as the echo of the explosion died away. The man who had thrown the grenade was running back down the stairs after her. On the top floor, she saw another black-clad figure toss something considerably larger than a grenade onto the floor outside the bathroom, then run like hell back into the library, slamming the door behind him.

Covered in broken pieces of wood and plaster and tile, Mac sat up. The thick sides of the old bath had shielded him from the direct blast of the grenade. Dust and smoke swirled through the room, but he could still see clearly enough to make out what was outside the broken doorway, a squat cylinder lying on its side on the smoldering carpet…

“Bastards!” he hissed.

He knew what it was. He’d used similar devices in his own career.

It was a fuel-air explosive charge. An antiterrorist weapon, designed to clear large but confined spaces like cave systems by releasing a cloud of highly flammable vapor and then detonating, creating a massive fireball that raced outwards to fill every nook and cranny, consuming whatever lay in its path.

And it would work just as well in a London house as an Afghan cavern.

A gray mist spewed from the cylinder.

“Nina!” he yelled as he stood. “Get out of the house! Get out!”

The desperate urgency in his voice spurred Nina to action even more than the sight of the gunman racing down the stairs. She jumped up, fear overcoming the pain as fragments of stained glass stabbed into her bare foot, and sprinted for the front door.

The man charged after her, rapidly closing the gap-

A small electrical arc cracked across the nozzle of the explosive cylinder.

A millisecond later, the vapor cloud ignited, expanding at near-supersonic speed into a ball of liquid fire that incinerated everything it touched as it swept outwards to fill the bathroom, the upper landing, the entire hall-

Nina cleared the front door and ran down the stone steps as the bomb detonated. She threw herself flat.

The house’s windows exploded in rapid floor-by-floor succession, huge jets of flame bursting through them and boiling skywards. Another burst of fire erupted from the front door as the gunman hurtled through it, the blast propelling him over Nina to land in the street. He yelled and rolled frantically onto his back, trying to smother his burning clothes.

Nina looked up. One of her attackers was occupied with his own survival, the other had escaped through the back of the house and would have to run around the block to reach her-this was her chance to flee and find help.

She stood-

And a metal dart thudded into her thigh.

There was a white van parked across the street, another man climbing out of its side door with an odd-looking gun in his hand.