"How quickly will it work?"

"Almost immediately. You need to apply it in the morning. The process will begin at once, and within thirty-six hours it'll be unstoppable. There won't be anything to see, of course-not to begin with-but in about three weeks you'll have the attention of the entire world." Straik paused. "What about the shooting? All done?"

"I'm sending Myra to Elm's Cross tomorrow. We're closing it down."

"Getting rid of the evidence."

"Exactly."

"Well, in that case . . ."

Straik stopped. And in the silence, somehow Alex knew that something had gone wrong. Crouching behind the picture, he froze, afraid that the sound of his breathing or his heart beating would give him away.

"Someone has been in my office," Straik said.

"What?" The word came out like a whiplash.

"My desk . . ." Straik picked something up, and even without seeing it, Alex knew what it was. The memory stick that had been in the computer when he arrived. He had taken it out to insert his own-but he hadn't had time to replace it. "This was in my USB port when I came down to meet you," Straik said. "I loaded it myself. Someone's taken it out."

"Are you sure?"

"Of course I'm sure."

"Your secretary could have been in."

"She's not here."

Alex realized he couldn't hold his position much longer. He was desperate to straighten up, to allow his muscles to stretch. At least there was one good thing. The hiding place was so small that neither of the two men would suspect for a minute that anyone else was still in the room. But he had to know what was going on, even at the risk of giving himself away. Very slowly, he leaned forward a few inches to have a glimpse in the mirror. McCain was holding the memory stick. Straik was hunched over his computer, tapping furiously at the keyboard, his little eyes focused on the screen. Two pin-p.r.i.c.ks of red had appeared in his cheeks.

"This computer has been compromised," he announced.

"Compromised?"

"Someone has attempted to download doc.u.ments and files from the main drive. For all I know, they may have succeeded." Straik s.n.a.t.c.hed up a telephone and dialed a number. There was a brief pause. Then he was answered. "This is Leonard Straik," he said. "I want an immediate status report." Another pause. Alex wondered what was being said at the other end of the line. It wasn't hard to guess. Then Straik spoke again. "I want you to put out a condition double red alert," he snapped. "All personnel to a.s.semble immediately. This is not an exercise. We have a major security breach."

He hung up. "We have an intruder," he said to McCain. "Ten minutes ago, our entire surveillance system went down. Someone must be jamming the signal. This is what they were after." He nodded at the computer. "They must have left seconds before we arrived."

"What's a double red alert?"

"Any unauthorized person found wandering inside the Bio Center will be killed . . . no questions asked."

"Don't you have a bunch of schoolchildren here?"

"I haven't forgotten that, Desmond. I'm not an idiot-whatever you may think. My staff have special instructions." He turned off the computer. "I'm going to the control center. Are you coming?"

"Absolutely." It struck Alex that McCain sounded more amused than alarmed. But that seemed to be his character. Whatever he might be up to, he didn't believe that anyone could get in his way.

The two of them stood up. Alex heard the swish of cloth as Straik came out from behind his desk. They went over to the door. It opened, then closed. Alex was on his own.

Gratefully, he uncurled himself from behind the picture. For a moment he stood where he was, trying to collect his thoughts. He was probably safe while he was in Straik's office, at least for the time being. Security would be searching for him-but this was the one place they wouldn't look. Even so, he couldn't stay here forever. With an intruder on the loose, the school visit might be cut short and the bus sent back to London. Alex had to be on it. He couldn't be left behind.

It was worse than that. Alex realized that his only chance of survival was to get back to Mr. Gilbert and the others. There had been nothing accidental about the death of the whistle-blower, and no matter what Blunt might have said, there really was something seriously unpleasant going on at Greenfields. Why else would the director be so keen to see that any intruder was killed? Alex had to get back to his cla.s.s. No guard was going to fire at him when there were witnesses. Once he was back with the others, he would be safe . . . just one bored student among many.

He headed for the door, about to leave, when he noticed a gla.s.s vial resting on Straik's desk. It was a test tube, sealed at the top, with a muddy gray liquid inside. This must be the "sample" that he had heard the two men talking about. Alex had no idea what it contained, but another thousand gallons of it were on their way somewhere abroad. He still had the memory stick in his pocket, but on an impulse he went over and took the test tube too. Smithers would a.n.a.lyze it. And that would be the end of it. The liquid would surely reveal whatever was being planned.

He opened the door carefully, checked there was no one in sight, then stepped outside. He had decided to head back the way he had come. He had no idea where his friends were and he was furious that he had no way of communicating with them. Normally, he would have called Tom or James . . . but all their mobile phones had been left on the bus. What had the woman, Dr. Beckett, told them? The laboratories first. Then the greenhouses and storage centers. Finally, the lecture theater. Surely they couldn't be too hard to find.

Alex closed the door behind him and sprinted back around the corner, his feet making no sound on the carpet. The gla.s.s bridge was ahead of him, but even as he approached it, he heard men running toward him and spun back, ducking into a storage cupboard a second before they appeared. There were three guards and they were all armed. Alex watched them run across the bridge and disappear down another pa.s.sage. Above his head, he noticed a light flashing red. He gritted his teeth. This had turned into a cat-and-mouse game with only one mouse and an awful lot of cats.

The bridge was clear and he crossed it into what he had thought of as the administrative block. He went back down the stairs but immediately realized that he had forgotten which way he had originally come from-left or right. The trouble was that every direction looked the same. He tossed a mental coin and set off, knowing almost at once that he was lost. He still had the postcard with its guidance system in his back pocket but it couldn't really help him now. All that mattered was to keep moving and not to be seen.

"Stop!"

The guard had stepped out of nowhere, blocking his way. He had a machine gun dangling around his neck and he was already fumbling with it, bringing it up and around. Alex turned and ran. He had taken no more than ten steps when a neon light fitting exploded with a shower of sparks and broken gla.s.s. At the same time, the walls and ceiling showered plaster on him. Alex hadn't heard much more than a whisper, but the guard was clearly firing in his direction, the bullets streaming over his head. The gun must have some sort of silencer attached to it . . . and of course, that made sense. These were the "special instructions" that Straik had issued. They couldn't risk the sound of gunfire, not when they had forty schoolkids on the site.

Alex hurtled down another corridor, past a series of open doors. He pa.s.sed a laboratory, surprisingly cluttered and old-fashioned, with plant specimens on the work desks and bottles of different chemicals on the shelves. A woman in a white coat, holding a petri dish in the palm of her hand, looked up and momentarily caught his eye. Behind her, a man was taking a tray of flowers out of what looked like an industrial fridge. Alex wondered if his cla.s.s had been here, perhaps a few minutes before. He was tempted to stop and ask. He could still pretend to be lost. He decided against it.

Double red alert. He had so far been spotted by one guard, and the fact that he was a boy in a school uniform hadn't made any difference at all. These people wanted him dead.

He heard shouting behind him. There was another light flashing in the corner of his eye. Alex hadn't even slowed down. He saw a gla.s.s door ahead of him and sprinted toward it, palms outstretched, praying that it wasn't locked. He pushed. It opened. He almost fell through as another blast of bullets fanned silently through the air, punching dotted lines across the wall beside him. But now he was outside and running. He saw the sleek white exterior of the lecture theater on the other side of the lawn, but he couldn't reach it. More guards in electric vehicles were racing toward him, moving fast. Alex felt a surge of despair. How could he have allowed Alan Blunt and MI6 to talk him into this? He'd promised Jack he wouldn't get into trouble again. He'd promised Sabina. More than that, he'd promised himself.

Anger spurred him on. He reached one of the greenhouses and plunged in through two sets of doors. It had been cold outside, but here the climate was subtropical. Hundreds of plants were arranged on shelves, some just a few inches tall, some bending against the roof high above. The greenhouses were actually more like gla.s.s factories, divided into dozens of different rooms, each one joined to the other by a maze of interlinking corridors. Huge silver pipes and watering systems snaked across the ceiling. There were banks of machinery controlling the lights, the temperature, and the humidity in all the different areas, ensuring perfect conditions for all this artificial life. Alex had to be safe here. The guards might have followed him in, but there were plenty of hiding places. Provided he kept moving, there was no way they would be able to find him.

The next attack took him completely by surprise. A cascade of bullets that seemed never-ending. They came from all sides, determined to kill the intruder even if it meant destroying the entire complex. Alex didn't hear a single shot, but inside the greenhouse the noise of bullets smashing gla.s.s was deafening. Windows shattered all around him. Alex threw himself to the ground as shards of gla.s.s, thousands and thousands of them, showered in all directions. Inches above his head, the plants were shredded, the very air turning green as it was filled with tiny cuttings of stalk and leaf. Terracotta pots exploded, earth showering out. Brightly colored flowers tore themselves apart. And still the bullets kept coming, hammering into the machinery, ricocheting off the metal pipes. Alex could just make out the dark shapes of the guards surrounding the building, destroying it. He wondered if they had all gone mad. Or was it that the work at Greenfields was finished and nothing mattered anymore, so long as n.o.body was able to escape with its secrets?

He scurried forward on his hands and knees, trying to lose himself farther inside the complex. He came to a brick wall with another bank of machinery and crawled behind it, putting a solid barrier between himself and the gunfire. n.o.body could see him here. He patted his fingers against his forehead. When he examined them, they were stained with blood. None of the bullets had hit him. It must have been the falling gla.s.s. He brushed it out of his hair and off his shoulders. What must he look like? What would Mr. Gilbert say if he ever turned up?

He had to find the school tour! Surely they must have heard all the racket, even if the guards were using silencers. Another corridor led into the distance, this one with mirrored tiles instead of gla.s.s. He set off, still keeping low. Suddenly he was surrounded by brickwork. He had entered some sort of equipment room with spades and wheelbarrows. He could have been in an ordinary garden center rather than a top-secret research inst.i.tute. There were even bags of fertilizer . . . as if he needed reminding of the sort of trouble he was in.

Somehow he had to find a way back outside. Then he would cut back to the lecture theater and hope to join the rest of Brookland there. At least he seemed to have lost the guards with their machine guns. Perhaps they were scouring through the wreckage, looking for a body. Alex checked the test tube that he had stolen from Straik's office. He had been carrying it in his top jacket pocket, and fortunately it was still in one piece. He slipped it back in and set off again, heading for a set of solid-looking doors and a sign: STRICTLY NO ADMITTANCE. AUTHORIZED PERSONNEL ONLY. The doors were locked and hermetically sealed, but there was another reader set in the frame. Alex still had the library card. He had reprogrammed it to open Straik's door, and presumably Straik had access to every zone in the Bio Center. So . . .

He tried it. It worked. The doors opened. Alex went in, smiling as they clicked shut behind him. It might well be that the guards were unable to follow him in here. How many of them, after all, would have been authorized?

He only realized where he was when it was too late. The shape of the building, the intense heat, the moisture running down the gla.s.s panes . . . all these should have warned him. But the door had already locked itself, and looking back, he saw that there was no reader on this side, no way back out. He stood where he was, feeling the heavy air on his cheeks and forehead. His clothes were already sticking to him. Something was buzzing loudly over his head. Alex closed his eyes and swore.

He had walked into the Poison Dome.

12.

h.e.l.l ON EARTH.

ALEX LOOKED AROUND HIM. He had once visited the greenhouses at Kew Gardens in London-and in some ways this was similar. The building itself was very elegant, the great dome supported by a delicate framework of metal supports. The whole area was about the size of a circular soccer field, if such a thing could exist. But unlike Kew Gardens, there was nothing beautiful or inviting about the plants that grew here. Alex examined the tangle of green in front of him, the trunks and branches crisscrossing each other, struggling for s.p.a.ce. They all looked evil, the leaves either razor sharp or covered in millions of hairs. He remembered what Beckett had said. These were mutant organisms. Touching just one of them would bring pain and death. Fruits in the shape of half-sized apples hung over his head, and rich, fat berries clung to the bushes. But they were all hideous colors, somehow unnatural, warning him to stay away. He could hear droning. There were insects in here and they were big ones, from the sound of them. Bees, perhaps something worse.

Alex's skin was already crawling, but he forced himself not to move. The information that the Beckett woman had given him when he arrived might even now save his life. He mustn't brush against any of the plants here. They had been altered so that they were a hundred times more deadly than nature intended. And there weren't just plants. She had talked about the interaction of poisons. And so there were spiders and snails and . . . of course, the bees. Why had Straik created this place? h.e.l.l on earth. What was he trying to prove?

Alex couldn't go back. He remembered the shape of the dome, with the corridors branching out like points of the compa.s.s. He had come in as if from the south. Now he had to reach the other side and one of the other three exits. Two in and two out . . . that must be how it worked. From what he could remember, the lecture theater must be directly in front of him. So all he had to do was walk straight. And at least there was a path, a boardwalk made of wooden planks, stretched out ahead. And n.o.body would be looking for him in here. n.o.body would be stupid enough to follow him in. He might be stung, bitten, poisoned, or scared to death, but at least he wouldn't be shot.

So . . .

There was no other way.

Alex moved forward, very slowly. Touching nothing. Not making a sound. If he was going to get out of here alive, he would have to take it literally one step at a time. Beckett had mentioned snakes . . . the taipan. Alex knew it to be the most venomous land snake in the world, fifty times more toxic than the cobra. But it was also nervous. Like most animals, it wouldn't attack a human unless it was threatened. So provided he didn't brush against anything, touch anything, step on anything, or alarm anything, he might come out of this all right.

One step at a time.

He followed the wooden boardwalk. The plants were horribly close to him. The nearest of them was an oversized thistle that seemed to be straining to break free and attack him, like an angry dog. Then came a squat, ugly tree corks.c.r.e.w.i.n.g out of the earth with green scalpel blades instead of leaves. The smell of sulfur rose in his nostrils. The path was crossing a volcanic pool. A creeper hung in front of him. He resisted the urge to brush it aside and bent low, contorting himself to avoid coming into contact with it. If he made one miscalculation, even so much as an inch, he might dislodge something, and he knew that a single touch could finish him. Everything here was his enemy. Something buzzed close to his head and he jerked around, unable to control himself. His sleeve brushed against a jagged-edged nettle, but fortunately, the material protected him from the bristling hairs-or neurotransmitters, as Beckett had called them. Alex shrunk into his jacket, pulling it around him. Every fiber of his being was concentrated on the way ahead.

Something slithered onto his foot.

Alex stopped. He even stopped breathing. It was as if someone had drawn a noose tight around his throat. Trying not to panic, he looked down. He could already tell from the weight that this wasn't a snake. It was too small, too light. And it hadn't slithered, it had crawled. For a moment he couldn't see it and thought that perhaps, after all, he had imagined it.

He hadn't. It was almost worse than a snake. A glistening centipede, at least eight inches long, had settled on the top of his sneaker. The creature could have been drawn by a demonic child: red head, black body, bright yellow legs that seemed to be writhing with antic.i.p.ation. Alex knew what it was. He had seen something exactly the same once on television. The giant redheaded centipede. Also known as the giant desert centipede. How had the narrator described it? Unusually aggressive and extremely fast . . .

And this one had decided to stretch itself out on his foot. What if it decided to explore a little farther, over his ankle and up his pant leg, for example? Alex stood as still as a statue. Without making any sound, he was screaming at the insect. Go away! Go and explore a sulfur pit. Make friends with a marbled cone snail. But leave me alone! Go away! Go and explore a sulfur pit. Make friends with a marbled cone snail. But leave me alone! Alex could see its antennae twitching as it made up its mind. He looked fearfully at his bare flesh just inches above his sock. He couldn't bear it any more. He suddenly lashed out, using every muscle in his leg as he kicked at the air. He thought the centipede would still cling on. It might get tangled in his laces. He was certain he was going to feel its bite. But when he looked down again, it was no longer there. He had managed to shake it free. Alex could see its antennae twitching as it made up its mind. He looked fearfully at his bare flesh just inches above his sock. He couldn't bear it any more. He suddenly lashed out, using every muscle in his leg as he kicked at the air. He thought the centipede would still cling on. It might get tangled in his laces. He was certain he was going to feel its bite. But when he looked down again, it was no longer there. He had managed to shake it free.

He needed a weapon . . . anything to protect himself from whatever might come next. Why couldn't Smithers have built a flamethrower into his Simpsons pencil case? Alex reached into his backpack once again. He had the two gel pens, but the last thing he wanted to do in here was set off an explosion . . . it would just advertise his presence to every living thing. That just left the pencil sharpener with the diamond-edged blade. He took it out and unfolded it three times, the plastic swiveling on concealed hinges. He was left with something that looked like a tiny ax or meat cleaver, barely three centimeters long. It might be useful for cutting through wire or even gla.s.s, but it wasn't much good for anything else. Even so, Alex felt a little more confident having it in his hand.

Where was the other door? The guards must still be looking for him, and he knew he had to get a move on, to find his way out of here as quickly as possible. But even so, he didn't dare hurry. He took another step and his foot came down on a little cl.u.s.ter of mushrooms, crushing them. Pale yellow liquid, like pus, oozed out from beneath his sole. A moth fluttered briefly in front of him. It was hard to believe that he was in an artificially created environment, a greenhouse-and not lost in the jungle. The pathway took him past a pool of boiling mud, bubbles rising slowly and heavily to the surface. A tall, twisted tree with lianas trailing from its branches grew beside it. Alex looked up, then ducked back as a globule of milky white syrup splashed down, oozing out of the bark. It missed his face by millimeters and he knew that if it had hit his eyes, he might well have been blinded.

The path curved around and Alex found himself in a slight clearing with a tiny river in front of him and a j.a.panese-style bridge. The pretty humpbacked structure looked ridiculous in this artificial jungle. Who could possibly want to come for a walk here among so much death? He could no longer see the gla.s.s windows that made up the outer walls of the Poison Dome and guessed that he must be at its very heart. Well, at least if he was halfway in, that meant he was also halfway out. Something buzzed past his head and he just caught sight of a giant wasp, legs trailing, barely able to stay in the air as it struggled against its own weight. What horrors were going to come next? He had to get out of here.

He crossed the bridge, still moving slowly. Silvery water flowed beneath, and as Alex pa.s.sed across, it suddenly erupted in a frenzy. Some sort of fish life had detected his presence. Piranha . . . or something worse. Alex was beginning to wonder if the dome had really been built as a scientific experiment or if it wasn't just some huge toy, the fantasy of a sick mind. Straik might pretend to be studying poisons. In fact, he seemed more interested in sudden death.

He stepped off the other side of the bridge. That was when the man appeared.

It was a guard-or a gardener-dressed in a white protective suit that began at his ankles and continued all the way to his neck. His feet were weighed down by heavy-duty boots and he was wearing gloves that doubled the size of his hands. His head was completely enclosed in the sort of helmet that a beekeeper might wear, except that instead of a net, his face was covered by a plastic sheet. Alex was aware of two hostile eyes glaring at him, a small nose, and a mouth curled in a sneering smile. The rest of the man's features were hidden. He was holding a machete. He was pointing it directly at Alex.

Alex stopped with the bridge behind him. "Hi," he said. "Are you the park attendant? Because if so, maybe you could show me the way out."

The man tightened his grip on the weapon. Alex knew what was about to happen and he was ready for it. As the machete swung through the air, the blade aiming for his neck, he dropped down, then threw himself forward, ducking underneath the man's arm. For just a second, Alex was behind him and he slashed upward with his own, miniature blade. The man didn't even feel it. He spun around and brought both his hands plunging down, using the handle of the machete as a club. It smashed into Alex's shoulder and the pain ricocheted along his bones and muscles, all the way to his wrist. His hand fell open and the little knife dropped away.

The man came at him again, this time swinging the blade to force Alex away from him. Alex took one step back, then another. At the last second, he remembered the water behind him. The man was about to feed him to the fish. Alex stopped with his heels on the very edge of the bank. The machete sliced the air in front of him and at once he lashed out, his fist plunging into the man's abdomen. The protective suit absorbed much of the damage. Alex felt the hardened material take the skin off his knuckles. But the man had been winded and fell back. Alex lashed out with his foot, catching the man on his arm. The machete spun away and landed, point down, in a flower bed.

The man charged straight at him, almost knocking Alex off his feet. Alex was terrified he was going to step on a nettle or fall backward into one of the flower beds. The flowers growing near the river were like porcupines, with huge spikes and bulging, overripe berries that could have been disease-ridden eyes. For a moment Alex lost his balance and he lifted an arm to steady himself. He touched a spider's web hanging from a branch. He hadn't even seen it, but he felt it at once. A single strand of the web had wrapped itself across the flesh on the back of his hand. It burned into him like acid. Alex cried out.

The man reached for the machete, took hold of it, and suddenly he was coming again at Alex, chopping the air with a series of vicious blows. Alex looked left, right, then behind him. He had almost backed into another tree. The bark looked innocent enough, but he didn't dare touch it. It might contain ricin or botulin or any other toxin that Beckett had forgotten to mention. How far away was it? Alex judged the distance carefully, then stood his ground. The man stumbled toward him. The heavy protective suit he was wearing was slowing him down. The blade slashed toward Alex's neck. At the very last second, Alex ducked and, just as he had hoped, he heard the clunk as it bit into the tree. The man pulled at it, but it was stuck fast. And that was when Alex twisted around and slammed his foot into the man's chest, putting all his strength behind it.

The man, thrown backward, slipped and fell on his back, landing in one of the beds of porcupine flowers. Even now, his suit should have protected him. But he had no way of realizing what Alex had done. Before he had lost it, he had used the little pencil-sharpener knife to make a slit that ran all the way from the man's waist to the back of his neck. There was a gap now that had allowed the spikes to go all the way through. The man screamed. Behind the mask, his eyes bulged and his entire body began to jerk, his legs kicking helplessly. Alex watched in horror as gray foam began to pour out of his mouth. Then suddenly his arms shot out and he lay still.

Alex didn't stay a moment longer than he had to. The noise of the fight would have disturbed whatever else was living in this nightmare place. If there were any other men working inside the dome, they would be on their way to investigate. He'd had enough. Still forcing himself not to panic, he pressed forward. A few minutes later, he was finally rewarded-a door! This one opened from the inside. Alex felt a great wave of relief as he swiped the card and pa.s.sed through. The door swung shut. He had left the Poison Dome behind.

He examined the back of his hand. The web had left a white line running from one side to the other and the whole thing was swollen and painful. Well, he just had to be grateful that he hadn't actually met the spider. He rubbed the wound, but that only made it feel worse. He would just have to ignore it until he could get medical help. Where was he? The dome had brought him into another greenhouse, this one filled with troughs of what looked like wheat. He wasn't safe yet, but at least he was away from the shooting. Maybe the guards thought he was already dead.

He found a door and made his way outside again. In the distance he could hear shouting and two electric vehicles shot past, carrying more guards toward the noise. The lecture theater-white and modern-was right in front of him. Alex didn't know if the cameras were still jammed, nor did he care anymore. He was tired. His hand was hurting. His shoulder-where he had been hit with the handle of the machete-was on fire. There was still broken gla.s.s in his hair and he knew there must be quite a few cuts on his forehead and face. The next time Mr. Gilbert offered him a school trip, he would say he was sick.

He staggered forward, heading for the lecture theater. Maybe the rest of the school would already be there. He would slip in without being noticed and join the rest of the group. He could already see himself dozing off during the rest of whatever talk was going on.

Then the doors opened. Two guards stepped out. They saw Alex at the same moment that he saw them.

It wasn't over yet.

Alex turned around and ran.

13.

EXIT STRATEGY.

TOM HARRIS WAS GETTING WORRIED.

Almost an hour had pa.s.sed since Alex had slipped away, disappearing into a restroom like some superhero about to change into costume and save the world. Only it wasn't like that. Tom knew that Alex didn't really want to work for MI6. He had said as much when the two of them were out together in Italy. So why had Alex chosen to go back to it all-and what could be such a big deal about a research center that seemed to be spending most of its time designing the perfect tomato?

After Alex had gone, the rest of the school party had been taken to one of the laboratories, where an earnest young scientist with a neatly trimmed beard had shown them the chemical process that put new DNA into a single plant cell. Tom had barely listened. He didn't find it easy to concentrate at the best of times. Now, his parents had recently separated. His father was living on his own in a motel in south London. His mother had taken up smoking again. They were both overachievers with a pile of diplomas between them, but what good had it done them? If Tom had his way, he would drop school entirely.

As they had moved from one laboratory to the next, Tom had pa.s.sed a window and had found himself looking for Alex. There was n.o.body in sight. But during the next demonstration-something to do with plants freeze-dried in liquid nitrogen-he had noticed a red light begin to blink discreetly in the corner of the room. Beckett had clearly seen it too. Tom saw her face change, a look of concern creeping into her eyes. It was an alarm. He was sure of it.

And then, in the distance, he heard something. The sound of breaking gla.s.s-a lot of it. Everyone else was too busy listening, taking notes. But Tom knew what it meant. Alex was on the run. Part of him was tempted to sneak out and join him.

It was lucky he didn't. As soon as the demonstration ended, Beckett insisted on a roll call to check that everyone was there, and-as promised-Tom stood in for Alex, doing a reasonable imitation of his voice.

"Rider?"

"Here, sir."

Only James Hale, standing next to him, saw what was happening and glanced at him quizzically. Tom shrugged but gave nothing away.

And now they were in some workshop, two floors down, underground. Tom wondered if they had been brought here on purpose, to stop them from hearing or seeing anything that might be going on outside. Another scientist-this one young, female, and Chinese-had arrived to show them the famous gene gun, developed, they were told, by the director of Greenfields. It was a rather ordinary-looking piece of equipment that resembled a small metal safe with a gla.s.s door. Nonetheless, this was at the heart of GM technology, the woman said. She opened the door and placed a round petri dish inside.

"The gene gun is a very effective way to deliver new DNA into a plant," she explained. "This is done by a system known as Biolistic Particle Delivery . . ."

As she continued, Tom noticed a guard, dressed in khaki, steal into the room. He approached Beckett and whispered urgently into her ear. Tom wasn't surprised when, a moment later, she stepped forward, interrupting the talk.

"I am very sorry, boys and girls," she exclaimed. "I am afraid we are going to have to end your visit to Greenfields. An emergency situation has arisen and you must return to your school bus at once."

"Wait a minute . . . ," Mr. Gilbert began. His face was indignant. They had driven a long way to visit the center and they had only been here for an hour.

"There will be no argument," Beckett snapped. "We will take the back staircase. Your driver has been instructed to meet you around the side of the building."