Delacourt hotel, watching the doors to 44th Street. He could see a small but excited crowd through the glass, hotel staff keeping back anyone who had no legitimate business in the building.

Almost eight p.m. The tide would reach its highest point at 8.14, and he still needed Lola’s go-ahead before the operation could begin. Matt would have to work fast.

Someone pushed through the throng outside, and was briefly quizzed by a doorman before coming in: Zec, dressed in a heavy overcoat and seeming irritated at having his entry challenged. He spotted Eddie and sat next to him. ‘What’s going on?’ he asked, indicating the bustle outside.

‘Paparazzi,’ said Eddie disinterestedly. ‘Some celebrity’s in the hotel.’ He gave the Bosnian a sour look. ‘You got the thing?’

Zec handed him a small memory card. ‘Your wife’s handprint. Put it in the prototyper, and the machine will do the rest. Just remember to wait until it cools to body temperature before putting it on the scanner.’ His eyes narrowed. ‘I was also told to remind you what will happen to your wife if you do not bring me the Codex.’

‘I’m not fucking deaf,’ Eddie growled, aware the statement might not be entirely truthful. ‘You already told me.’

‘Just doing my job.’

‘Your wife and son know about your job?’ Zec was unprepared for the question, and looked sharply at him. ‘Think your wife’d approve of you threatening to kill mine? Kid proud of Daddy the murderer?’

‘Shut up,’ Zec snapped. ‘The only people I have killed are legitimate mission targets. Civilian casualties were not my fault.’

‘Well, that makes it all better, dunnit?’ Eddie regarded him sourly. ‘No way Hugo would have worked with you if you’d told him that. But who needs morals when you’ve got money, right?’ The accusation appeared to sting the Bosnian, which gave Eddie a moment of gratification. ‘Now, I want to talk to Nina.’

‘I thought you might.’ Zec made a call. ‘Mr Khoil? Chase wants to speak to his wife.’ He listened to the reply, then handed the phone to Eddie.

‘Mr Chase,’ said Khoil. ‘I hope you are ready to bring me the Codex. Otherwise, you know what will hap—’

‘Yeah, yeah, spare me the fucking threats,’ Eddie snapped. ‘I already had them from your errand boy. Where’s Nina?’

‘She is here with me.’

A pause, a hollow echo down the line, then Nina spoke. ‘Eddie? Are you okay?’

‘I’m fine - what about you?’

For a moment, it seemed that she hadn’t heard him. ‘Eddie? Are you there - oh, thank God. Yeah, I’m okay. Look, Eddie, you can’t go through with this. I know part of what the Khoils are planning. They—’

‘Enough,’ said Khoil. The faint echoing effect disappeared. ‘Mr Chase, it is time to bring me the Codex. Do so, and your wife will be returned to you unharmed.’ With that, the line fell silent.

Eddie returned the phone to Zec, using all his willpower not to say out loud the thought dominating his mind: Khoil was lying. Nina wasn’t with him, the delay of the satellite connection proving she was still in India. The moment Khoil - who from the instant response on his side of the call clearly was in the States, eager to take personal delivery of the Talonor Codex - got what he wanted, she would be killed.

And so would the man who obtained the Codex for him, Eddie knew. But all he could do for now was play his part - and hope that Plan B worked.

His phone trilled. ‘Lola?’

‘Everything’s ready,’ said Lola. ‘You remember the locker numbers?’

‘Burned into my mind.’

‘Okay. Good luck.’ She rang off.

Eddie stood, picking up a large black leather briefcase with gleaming steel trim. ‘That was the go-signal,’ he told Zec. ‘I’ll meet you back here when I’m done.’

‘With the Codex.’

‘Obviously with the fucking Codex. You just be ready with Nina.’ He headed for the doors, glancing back at Zec . . . then past him, to a couch. Dressed in a suit, reading a newspaper, Mac briefly looked up at him. At his feet was another black briefcase.

Eddie stepped outside, feeling the bite of the December cold as he pushed through the crowd and walked to the end of 44th Street. The United Nations complex rose on the other side of First Avenue, a towering grid of lights against the dark sky.

He raised his phone again. ‘Matt? It’s Eddie. I’m ready.’

‘Roger that, mate,’ said the Australian. ‘We’re in the pipe, five by five.’

Karima popped up through the hatch to the lower deck. ‘Eddie just called. He’s going in.’ She ducked back. With a last look round for any boats that might belong to the NYPD’s Harbor Unit, Rad climbed down after her.

Matt Trulli had set up shop in the small cabin, two laptop computers and a complex remote control unit crammed on to a little table and secured with duct tape. A porthole was open, cold air coming through it; below it was a large spool of fibre-optic cable, the slender but strong glass thread running out through the window. The spool was connected to one of the laptops - and the other end of the line to the Remotely Operated Vehicle currently picking its way through a water pipe beneath the river’s western bank.

‘All right, you little beaut,’ Matt muttered, using two joysticks to guide the ROV. ‘Go on in there . . .’ On the laptop’s screen, a view from one of the robot’s cameras revealed a fat, plastic-sheathed cable disappearing into the darkness of the circular channel. The spool slowly turned, the robot’s fibre-optic control cable feeding out as it moved forward.

The ground under Manhattan was criss-crossed by myriad networks of underground conduits, from subway tunnels to steam pipes to the city’s telecommunications backbone. This particular system, originally constructed in the early twentieth century to provide the city’s fire hydrants with a supply of water straight from the river, had been out of use for almost a quarter of a century, superseded by more powerful pumping systems - until an enterprising telecoms company realised they were the perfect way to spread the hundreds of miles of fibre-optic lines needed to meet the city’s ever-growing demand for broadband without having to dig up half the streets in Manhattan.

The cables had been installed entirely by robots, designed to crawl through the narrow, flooded confines. Matt’s machine was following their tracks . . . but considerably more quickly. Servo was a metre-long, vaguely snake-like construct, made from three tubular sections linked by universal joints: a flexible torpedo able to bend and twist through narrow underwater spaces. The rearmost segment housed the propeller and steering vanes, the middle one the battery pack, while the front section contained cameras, lights and a folded manipulator arm.

Matt glanced at the other laptop, which displayed a graphic of the pipeline system overlaid on a plan of the United Nations. A blinking cursor showed Servo’s position, not far from the outline of the Secretariat Building. ‘What’s the time?’ he asked.

‘Eight oh four,’ Karima told him.

‘Christ, we’ve only got ten minutes to high tide. Pick up the pace, Servo!’ he told the screen as he thumbed the throttle wheel on one joystick. The fibre-optic spool turned faster.

‘Yes, just finishing some paperwork,’ Lola replied; then she lowered her voice. ‘I used Nina’s security code to give you access to the lockers. Just use your own ID when you get down there - it’s all in the system. As far as the guards will know, Nina’s given you authorisation to open them.’

‘They won’t check and find that she’s not here?’

‘But she is here,’ said Lola with exaggerated innocence as she tapped her keyboard. ‘The computer says she’s had one of the conference rooms booked all day. And computers are never wrong, right?’

Eddie grinned. ‘Thanks, Lola.’ Still carrying the heavy case, he went into Nina’s office.

He checked his watch. 8.10. Come on, Matt!

She looked at the view on the other laptop. The pipe divided ahead, one leg continuing straight on while the other made a ninety-degree turn. ‘Which way?’ Matt asked.

‘Left,’ she told him. ‘About twenty metres ahead there’s another junction. Turn right, and up.’

The pipe beyond the next intersection ascended at a forty-five degree angle. ‘Go left at the top,’ said Rad. ‘Then it’s a straight line to the junction box.’

‘Time?’ asked Matt as he piloted the robot towards the final turn.

‘Eight twelve,’ said Karima.

‘Two minutes to high tide . . . Christ.’ Another turn of the throttle.

The robot reached the top of the shaft. Alarmingly, it was instantly clear that the new pipeline was not completely full of water - a shimmering line sliced across its top.

The surface. The tide was at its highest. And it might not be high enough.

Matt shoved the throttle to full. On the screen, the conduit rushed past like something from a video game. ‘How far?’

‘Twenty metres,’ said Rad, staring at the map. ‘Fifteen . . .’

‘Watch out!’ Karima cried as something flashed into view ahead. An unidentifiable hunk of flotsam carried there by tidal currents blocked the way—

Servo couldn’t stop in time. The image spun crazily as the robot hit the obstacle . . .

And stopped.

‘Shit. Shit!’ Matt gasped. The view swayed dizzily as Servo reeled from side to side, but couldn’t pull free. He worked the joysticks, trying to make the robot squirm past the obstruction.

The water’s surface churned as backwash from the propeller created ripples - but even through the distortion Karima saw it was lower than before. ‘Matt! The water’s dropping!’

8.15. The tide was inexorably retreating.

Matt frantically jerked the controls. ‘Come on, Servo, you can do it! Come on!’

Still at full power. But still not moving.

‘Come on!’ Another twist, the camera rasping against the wall—

The view suddenly tumbled, the ROV corkscrewing down the pipe as it finally kicked free. Matt struggled to regain control. ‘How far, how far?’

‘Ten metres,’ said Rad.

The water level was still falling. The camera breached the surface, rivulets streaming down the lens.

Another few seconds, and the robot submarine would run aground . . .

‘Almost there!’ Rad cried. ‘Three metres, two—’

The pipe widened out. The ROV had reached an access shaft, a rusting ladder rising upwards. Matt reversed the propeller. Servo skidded to a stop on the bottom of the pipe, kicking up a bow wave.

‘Bloody hell,’ the Australian said, blowing out a long breath. ‘That was way too close.’

Karima examined the screen, seeing nothing but the pipeline disappearing into the distance. ‘Where’s the junction box?’

‘Above, in the shaft.’ He switched to a second set of controls to operate the ROV’s manipulator arm. It had a camera of its own mounted on its ‘wrist’; the view changed to an even more fish-eyed angle as the arm unfolded. The bottom of the image was dominated by a pointed probe: a cutter. ‘Let’s have a dekko . . .’

The camera tilted upwards, an LED spotlight flicking on to illuminate the shaft. The small lens made it hard to judge scale, the ladder seeming to have been made for giants, but the manhole cover at the top was probably less than three metres above. Far nearer was their objective - a fibre-optic junction box fixed to the shaft’s side. The main cable trunk ran through it, but another thick line emerged from its top and ran upwards, connecting the UN’s underground data centre to the rest of the digital world.

‘That’s it,’ said Rad, relieved. He indicated a lock on the box’s front panel. ‘Can you cut through that?’

‘No worries,’ Matt told him, guiding the arm closer. He flicked a switch; in seconds, the cutter’s tip glowed red hot. Carefully tweaking the controls, he touched the tool to the panel and moved it in a circle round the lock. The junction box’s casing was anodised aluminium, watertight and protected against corrosion, but the sheet metal was only thin. Molten droplets fell into the water as the cutter sliced through it.

In less than a minute, the entire lock dropped out of the panel. Matt switched off the cutter and retracted it, a robotic claw swinging up to take its place. It took hold of the edge of the burned hole and tugged until the panel opened. ‘Okay,’ he said. ‘Now what?’

Rad examined a schematic. ‘My source said that the diagnostic port is . . . this one.’ He indicated one of several sockets on the printout. Matt moved the arm to give them a better look at its real-life counterpart. ‘Second row, the bottom one.’

Matt pulled the arm back, tipping it down to look at Servo’s equipment bay. Inside was a length of fibre-optic cable, plug connectors on each end. ‘It’ll take me a few minutes to hook up the data link through Servo. You sure this program of yours’ll work?’

Rad dismissed the map from the second laptop’s screen, starting up another application. An unappealingly functional program titled Levenex FODN Diagnostic 3.2a appeared. ‘He says there’s a back door that’ll get us into the UN system. I’ve got the instructions - once we’re in, I can find the digital feeds for the vault’s cameras.’

‘This contact of yours,’ Karima said dubiously, ‘he is reliable, isn’t he?’

Rad smiled. ‘Well, I obviously can’t reveal my sources, but I trust him.’ A beat, the smile turning down a notch. ‘More or less.’

‘I see . . . Still, I’ll call Eddie and tell him we’re in position.’ She took out her phone.

Lola mouthed ‘Good luck’ as he passed. He nodded, then went to the elevators. Steeling himself, he pushed the lowest button and began his descent to the third basement level.

To his relief, his journey was uninterrupted, nobody else boarding the lift. At the bottom the doors opened, and he stepped out. He made his leisurely way to the secure storage area, wanting to give Rad as much time as possible to hack into the system.

But he couldn’t wait long. Every passing second was another slice off Zec’s deadline.

He arrived at the security station. ‘Evening, Lou. Henri.’

‘Workin’ late, Eddie?’ Jablonsky asked. Vernio looked up from the Nintendo DS he was using as a boredom-buster and nodded in greeting.

‘Yeah. Nina’s engrossed in some ancient wotsit or other. She asked me to check some files for her. It’s a glamorous job, being the special assistant to the director, eh?’

Jablonsky smiled, gesturing to the computer. ‘What do you need?’

Eddie inserted his ID and gave him the appropriate locker numbers. Vernio checked them on the screen. Tension rose up the Englishman’s spine. If Lola’s use of Nina’s security code had been discovered . . .

He couldn’t see the screen directly, but a faint wash of green over the Haitian’s face was enough to tell him that he had been approved. ‘Huh,’ said Jablonsky. ‘Lola just put some files in those lockers.’

‘You know how it goes,’ said Eddie, shrugging. ‘These scientist types: “I’ve finished with those, send them downstairs,” then half an hour later it’s, “Oh, I need to check that thing again, can you go and get it?” Still, at least I only need to take notes instead of faffing about signing ’em out of the vault.’

‘Small mercies, huh?’ Jablonsky let him through the gate and started down the central aisle. ‘This way.’

Eddie glanced towards the vault door as they turned off into one of the side stacks, navigating the maze until they reached the first locker on Eddie’s list. Jablonsky used a key attached to an extending chain on his belt to open it. One of the items inside was a large box file, held closed with an elastic band.

The guard moved to retrieve it, but Eddie stepped forward, putting down the briefcase. ‘It’s okay, mate. I’ll get it.’ He reached into the locker for the file - and while the other man’s view was obstructed, he surreptitiously jammed a rolled-up piece of cardboard into the rectangular slot in the lock plate.

The box file was heavy and awkward, an object clunking about inside. ‘Okay,’ he said, backing up. Jablonsky closed the door. It clicked. Eddie’s heart froze for a moment - if he couldn’t get back into the locker without a security key, it would seriously complicate things . . .

A thin line of cardboard was barely visible in the gap between the door and the frame, the bolt pressed against it. It had worked - just.

Covering his relief, he picked up the briefcase and followed Jablonsky to the next locker. No need to jam this one, as its contents were only a decoy, a collection of documents plucked from Nina’s office at random. This time, he allowed the security guard to collect them for him. The locker closed, they headed for the reading area, Eddie glancing up at the cameras along the route. The other guard would be watching him - but so would his friends.

He hoped Rad was as good as he claimed.

‘Here you go, Eddie,’ said Jablonsky. The reading area, a series of booths with high sides for privacy while reading classified material, was fortunately empty. ‘Sit where you like. When you’re finished, just wave - one of us’ll come get you.’ He indicated a camera, positioned so that while it couldn’t see anything being read, any occupants of the booths were still visible.

‘Cheers.’ Eddie went to the booth furthest from the main entrance and sat, putting down the briefcase and the box file and spreading the papers across the desktop. He made a show of finding some specific page until Jablonsky was out of sight, then opened the file.

Inside were two items: a three-litre plastic container of a thick transparent liquid, and an earpiece, taped to the top of the box. He removed the latter, tapping it twice as a signal before pushing it into his right ear.

‘Eddie, are you there?’ Karima. Her voice was distorted, his underground location making the signal crackle. ‘If you can hear me, give me a microphone check.’ He hummed a snatch of the Mission: Impossible theme. ‘Very funny. I’ve got him,’ she added for Rad and Matt’s benefit.

‘Is everything set?’ he whispered.

‘Rad’s still working on the cameras.’

‘How much longer will he need?’

Karima passed Rad her headset. ‘Eddie? I need another few minutes to Photoshop the last couple of cameras - but I also need to record the footage of you that I’m going to use to make a loop. Two minutes should be plenty.’

‘Anything special I should do?’

‘Move around a little so it’s obvious they’re not watching a freeze-frame, but make sure you’re in exactly the same position at the start and the end. You remember that movie Speed?’

‘Yeah, great film. I thought the sequel was a bit pants, though. What about it?’

‘The bad guy blew up the bus because the loop didn’t match exactly.’

‘I thought it blew up ’cause it crashed into a plane.’

‘Either way, it blew up! So you’ve got to get it right. Keep an eye on your watch, and be back in the same position when the two minutes are up. Ready?’

‘Yep.’

‘Okay, three, two, one . . . start.’

Eddie took up a neutral pose, pretending to peruse the documents. The two minutes that followed seemed to crawl by. A maddening itch started in the small of his back, but he resisted the urge to scratch it, knowing that any distinctive movements might be remembered when the footage was replayed on a continuous loop on the security monitors.

The second hand on his watch ticked round, passing the minute mark once . . . twice. ‘Okay, got it,’ Karima reported.

Eddie relaxed. ‘Great,’ he said, scratching his back.

‘Don’t move too much, though - you need to be in the same position when Rad starts the loop.’

‘How long will that be?’

‘Just give him a minute . . .’

‘Okay, I’m ready,’ he finally said. He switched to another program, the feeds from several of the security cameras arranged in a grid. The archives were empty, nothing moving except the constantly changing timecodes. Because the images were stationary, a single still frame with the original timecode masked out would serve to cover what Eddie was about to do. ‘Get back into position and I’ll give you a countdown. Karima will talk you though.’

On the camera covering the reading area, Eddie moved back into his neutral position. ‘He’s ready,’ said Karima.

‘What’re the guards doing?’ Matt asked, peering at the other video feeds.

‘They’re both at the security station,’ said Rad. ‘Okay, Eddie. Three, two, one . . . now.’

He hit a key. The images flickered as the live footage from the security cameras was replaced by Rad’s recordings. ‘Timecodes are okay,’ he said, anxiously checking each screen.

Karima was more concerned with the guards. If they had noticed the brief glitch . . .

They hadn’t. Both men remained seated, one still playing with his DS. ‘Eddie, it’s working. Go!’

He retraced his route to the sabotaged locker and tried the door. It rattled, the bolt catching the edge of the lock plate. ‘Shit,’ he whispered, pulling harder. If he couldn’t get in—

The cardboard wedge shifted, the bolt squeaking free. He froze. The locker was open, but if the guards had heard the sound . . . ‘Karima! The guards - are they moving?’

‘No,’ came the reply. He released a relieved breath, then turned his attention to the locker’s contents. Another box file was inside; he opened it, taking out a small but powerful LED torch on an elastic strap, a screwdriver with interchangeable heads, a pair of wrist straps, the suction cup, a heat-gun - a clone of the device attached to Matt’s ROV - and a small squeezable plastic bottle. Lining them up on the floor, he began to remove his clothes.

Through the earpiece he heard Matt humming ‘The Stripper’ - Rad’s computer was displaying the live signals from the cameras as well as the faked ones going to the guards’ monitors. ‘Tell Matt to pack that in,’ he muttered. The tune stopped.

He dropped his clothing to the floor . . . revealing a skin-tight polyurethane bodysuit. The super-slick garment had been designed for swimmers, reducing drag as they passed through the water to such an extent that they had been banned from professional competitions. But slickness - and tightness, the suit as constricting as a Victorian corset - were exactly what Eddie needed. Round his waist was a belt, also pulled tight.

He stuffed his clothes into the locker, then carefully shut the door and donned the wrist straps, clipping the heat-gun, the screwdriver and the suction cup to them. He then put the torch’s strap round his head and reached up to push the case and the silicone container on top of the lockers, followed by the plastic bottle.

Now the hard part began. Eddie jumped to grab the top of the lockers, feet against the doors. He was not wearing his usual boots, but close-fitting black climbing shoes, with rubber soles for maximum grip. As quietly as possible, he pulled himself up.

The space between the dusty surface and the suspended ceiling was barely more than a foot, but Eddie knew it would soon feel positively expansive. As the plans Lola procured had promised, there was a ventilation grille a few feet away. Pushing his belongings ahead of him, he crawled to it.

A minute’s work with the screwdriver, and the vent cover was freed at one end. He turned his attention to the other, only unfastening the screws halfway so that he could tilt the grille down on its makeshift hinge.

Shuffling to the end of the newly created ramp, he fastened the case to the back of his belt with another strap, then took the small bottle and squirted its contents over the front of his bodysuit. It was a lubricant; he had actually bought it from a sex shop. Looking into the darkness of the duct, however, he doubted he would get much pleasure from it.

‘Okay, I’m going in,’ he said, holding the suction cup. ‘Tell me if the guards move.’

‘I will, Eddie,’ said Karima. ‘Good luck.’

‘Thanks.’ He switched on the torch, pressed the suction cup against the metal floor and pulled himself inside.

It was worse than he had imagined. The short section of duct at the apartment had been clean; this was filthy, a grimy layer of God-knew-what having been drawn in by the ventilation system several floors above. But he continued, advancing with each hiss of the cup. The case and plastic container ground complainingly over the grille as he hauled them along behind him like a train.

Even with the benefit of the bodysuit, the duct was horribly cramped. He tipped his head to shine the light down the shaft. He had to cover over fifty feet before reaching the vault - where his first obstacle waited.

Karima’s voice crackled in his ear, the metal duct making radio reception even worse. ‘You okay, Eddie?’

‘Yeah,’ he grunted. He was sweating, the situation not helped by the tight synthetic suit.

‘Good. The guards are still at the desk.’

‘Okay.’ His movements had already become a routine. Release the suction cup, stretch and plant it against the metal six inches further ahead, apply suction, pull himself forward, repeat. The extra weight he was dragging made it more draining. His own body, pressed against the duct on all sides, was almost blocking the flow of air. The vent was getting stuffy, stifling - and it would soon become a lot hotter.

He fixed his attention entirely on advancing, trying not to think about the metal pressing in on him. Another six inches, and another. He looked ahead. The torchlight caught something in the distance.

He squinted, blinking away more sweat. The first obstacle: the metal baffle plates welded into the duct about thirty-five feet away. He would have to use the cutter to remove them.

Six more inches. Another six. His shoulders ached, but he had to endure the pain - the duct was too narrow for him to shift his weight. His back itched furiously, sweat building up inside the bodysuit.

Keep moving. Pull. Pull. Another foot covered—

The duct floor flexed under his weight. A flat metallic clonk echoed through the vent. He froze.

‘Eddie!’ Karima’s voice was anxious. ‘What was that?’

‘Are the guards moving?’ he whispered.

‘Yes! One of them just stood up!’

‘Maybe a locker popped open,’ Vernio suggested. It had happened before.

‘I’ll take a look.’ Jablonsky set off down the aisle.

The boat suddenly lurched as waves slapped the hull. A shaft of dazzling light shone through the open porthole. ‘You on the boat!’ boomed an amplified voice from outside. ‘This is the NYPD Harbor Unit. Come out on the deck, right now!’