It made his head spin to think about it. In the next few hours, he would earn more than he had managed in the last five years: a fantastic sum, paid in cash, right into his hands. It was the start of a new life. He would be able to buy his wife the clothes that she wanted, a car, a proper diamond ring to replace the band of cheap gold she had worn since they were married. He would take the boys, aged four and six, to Disneyland in California. And he would travel to London and see the Indian cricket team play at Lord’s, something he had dreamed about all his life but had never thought possible.

Until now.

He sat hunched up beside the window of the bus that was taking him to work, as he had done every day for as long as he could remember. It was devilishly hot. The fans had broken down once again and of course the company was in no hurry to replace them. Worse still, this was the end of June, the time of the year known in southern India as Agni Nakshatram —or “Fire Star.” The sun was unforgiving. It was almost impossible to breathe. The damp heat clung to you from morning until night and the whole city stank.

When he had money, he would move from this area. He would leave the cramped two-bedroom apartment in Mylapore, the busiest, most crowded part of the city, and go and live somewhere quieter and cooler with a little more space to stretch out. He would have a fridge full of beer and a big plasma TV. Really, it wasn’t so much to ask.

The bus was slowing down. Ravi had done this journey so many times that he would have known where they were with his eyes closed. They had left the city behind them. In the distance there were hills—steep and covered, every inch of them, with thick, green vegetation. But the area he was in now was more like a wasteland, with just a few palm trees sprouting among the rubble and electricity pylons closing in on all sides. His place of work was just ahead. In a moment, they would stop at the first security gate.

Ravi was an engineer. His identity badge with his photograph and his full name—Ravindra Manpreet Chandra—described him as a Plant Operator. He worked at the Jowada nuclear power station just three miles north of Chennai, the fourth largest city in India, formerly known as Madras.

He glanced up and there was the power station in front of him, a series of huge multicolored blocks securely locked inside miles and miles of wire. It sometimes occurred to him that wire defined Jowada. There was razor wire and barbed wire, wire fences and telephone lines. And of course, the electricity that they manufactured was carried all over India by thousands more miles of wire. How strange to think that when someone turned on their TV in Pondicherry or their bedside light in Nellore, it had all begun here.

The bus stopped at the security point with its TV cameras and armed guards. Following the 9/11 attacks on New York and Washington, nuclear power plants all over the world had become recognized as potential terrorist targets. New barriers had been added. Security forces had been enlarged. For a long time it had all been an incredible nuisance, with people ready to jump on you if you so much as sneezed. But it had been many years since 9/11. People had become lazy. Take old Suresh, for example, the guard at this outer checkpoint. He recognized everyone on the bus. He saw them at the same time every day: in at half past seven, out at half past five. Occasionally, he’d bump into them while strolling past the shops on Rannganatha Street. He even knew their wives and girlfriends. It wouldn’t have occurred to him to ask for ID or to check what they were carrying into Jowada. He waved the bus through.

Two minutes later, Ravi got out. He was a short, skinny man with bad skin and a mustache that sat uncomfortably on his upper lip. He was already wearing overalls and protective steel-capped shoes. He was carrying a heavy toolbox. Nobody asked him why he had taken it home with him when normally he would have left it in his locker; nobody had cared. It was quite possible that he’d had to fix something in the apartment where he lived. Maybe he’d been moonlighting, carrying a few jobs out for the neighbors for a few extra rupees.

The bus had come to a final halt beside a brick wall with a door that, like every door at Jowada, was made of solid steel, designed to hold back smoke, fire, or even a direct missile strike. Another guard and more television cameras watched as the passengers got out and went through. On the other side of the door, a blank, whitewashed corridor led to a locker room, which was one of the few places in the complex that wasn’t air-conditioned. Ravi opened his locker (there was a pinup of the Bollywood star Shilpa Shetty stuck in the door) and took out a safety helmet, goggles, earplugs, and a fluorescent jacket. He also removed a bunch of keys. Nuclear power stations do not use swipe cards or electronic locks on the majority of their doors. This is another safety measure. Manual locks and keys will still operate in the event of a power failure.

Still clutching his toolbox, Ravi set off down another corridor. When he had first come here, he had been amazed how clean everything was—especially when he compared it to the street where he lived, which was full of rubbish and potholes filled with muddy water and droppings from the oxen that lumbered along, pulling wooden carts between the cars and the motorized rickshaws. He turned a corner and there was the next checkpoint, the final barrier he would have to pass through before he was actually in.

For the first time, he was nervous. He knew what he was carrying. He remembered what he was about to do. What would happen if he were stopped? He would go to prison, perhaps for the rest of his life. He had heard stories about Chennai Central Jail, about inmates buried in tiny cells far underground and food so disgusting that some preferred to starve to death. But it was too late to back out now. If he hesitated or did anything suspicious, that was one sure way to get stopped.

He came to a massive turnstile with bars as thick as baseball bats. It allowed only one person in at a time, and then you had to shuffle through as if you were being processed, as if you were some sort of factory machine. There was also an X-ray scanner, a metal detector, and yet more guards.

“Hey—Ravi!”

“Ramesh, my friend. You see the cricket last night?”

“I saw it. What a game!”

Soccer, cricket, tennis . . . whatever. Sports were their currency. Every day, the plant operators passed it between them, and Ravi had deliberately watched Wimbledon the night before so that he could join in the conversation. Even in the cool of the corridor, he was sweating. He could feel the perspiration beading on his forehead and he wiped it away with the back of his hand. Surely someone would stop him and ask him why he was still holding on to his toolbox. Everyone knew the correct procedure. It should be opened and searched, all the contents taken out.

But it didn’t happen. A moment later, he was through. Nobody had so much as questioned him. It had gone just as he thought it would. Knew it would. Nobody had lifted off the top tray of the toolbox and discovered the twenty pounds of C4 plastic explosive concealed underneath.

Ravi walked away from the barrier and stopped in front of a row of shelves. He pulled out a small plastic device that looked like a pager. This was his EPD—or Electronic Personal Dosimeter. It would record his own radiation level and warn him if he came into contact with any radioactive material. It had already been set with his personal ID and security clearance. There were four levels of security at Jowada, each one allowing access to areas with different risks of contamination. Just for once, Ravi’s EPD had been set to the highest level. Today he was going to enter the heart of the power station, the reactor chamber itself.

This was where the deadly flame of Jowada burned. Sixty thousand uranium fuel rods, each one 3.85 meters long, bound together inside the pressure vessel that was the reactor itself. Every minute of the day and night, twenty thousand tons of fresh water were sent rushing through pipes both to cool the beast and to tame it. The resulting steam—two tons of it every second—powered the turbines. The turbines produced electricity. That was how it worked. In many ways it was very simple.

A nuclear reactor is at once the safest and the most dangerous place on the planet. An accident might have such nightmarish consequences that there can be no accident. The reactor chamber at Jowada was made out of steel-reinforced concrete. The walls were five feet thick. The great dome, stretching out over the whole thing, was the height and breadth of a major cathedral. In the event of a malfunction, the reactor could be turned off in seconds. And whatever happened in this room would be contained. Nothing could be allowed to leak through to the outside world.

A thousand safeguards had been built into the construction and the running of Jowada. One man with a dream of watching cricket in London was about to blow them apart.

The approach had come six weeks before at the street corner closest to his apartment: two men, one a European, the other from Delhi. It turned out that the second man, the one from Delhi, was a friend of Ravi’s cousin Jagdish, who worked in the kitchen of a five-star hotel. Once they had recognized each other, it seemed only natural to go for tea and samosas . . . particularly as the European was paying.

“How much do they pay you at Jowada?” The European knew the answer without having to ask. “Only fifteen thousand rupees a month, yes? A child couldn’t live on that amount, and you have a wife and a family. These people! They cheat the honest worker. Maybe it’s time they were taught a lesson. . . .”

Very quickly the conversation was steered the way the two men wanted it to go, and that first time, they’d left him with a gift, a fake Rolex watch. And why not? Jagdish had done them favors in the past, giving them free food that he had stolen from the kitchen. Now it was their turn to look after Ravi. The next time they met, a week later, it was an iPhone—the real thing. But the gifts were only a glimpse of all the riches that could be his if he would just agree to undertake a piece of business on their behalf. It was dangerous. A few people might be hurt. “But for you, my friend, it will mean a new life. Everything you ever wanted can be yours. . . .”

Ravi Chandra entered the reactor chamber of the Jowada nuclear power station at exactly eight o’clock.

Four other engineers went in with him. They had to go in one at a time through an air lock—a white, circular corridor with an automatic sliding door at each end. In many ways it looked like something out of a space-ship, and its purpose was much the same. The exit wouldn’t open until the entrance had closed. It was all part of the need for total containment. The five men were dressed identically, with safety helmets and goggles. All of them were carrying toolboxes. For the rest of the day they would carry out a series of tasks, some of them as ordinary as oiling a valve or changing a lightbulb. Even the most advanced technology needs occasional maintenance.

As they emerged from the air lock into the reactor chamber, they seemed almost to vanish, so tiny were they in these vast surroundings, dwarfed by the gantries and walkways—bright yellow—overhead, by electric hoists and cables, soaring banks of machinery, fuel rod transportation canisters, generators. Arc lamps shone down from the edges of the dome, and in the middle of it all, surrounded by ladders and platforms, what looked like an empty swimming pool plunged twelve yards down, with stainless steel plates on all four sides. This was the reactor. Underneath a 150-ton steel cap, millions of uranium atoms were splitting again and again, producing unimaginable heat.

Four metal towers stood guard in the chamber. If they were shaped a little like rockets, they were rockets that would never fly. Each one was locked in its own steel cage and connected to the rest of the machinery by a network of massive pipes. These were the reactor coolant pumps, keeping the water rushing around on its vital journey. Inside each metal casing, a 50-ton motor was spinning at the rate of 1,500 revs per minute.

The pumps were labeled north, south, east, and west. The south pump was going to be Ravi’s primary target.

But first of all he crossed to the other side of the reactor chamber, to a door marked EMERGENCY EXIT ONLY. The two men had explained everything very carefully to him. There was no point attacking the reactor cap. Nothing could penetrate it. Nor was there any point in sabotaging the reactor chamber, not while it was locked down. Any blast, any radiation leak would be contained. To achieve their aims, an exit had to be found. The power of the nuclear reactor had to be set free.

And there it was on the blueprint they had shown him. The emergency air lock was the Achilles’ heel in the fortification of Jowada. It should never have been built. There was no need for it and it had never been used. The idea of a passageway between the reactor chamber and the back of the turbine hall, where it opened onto a patch of wasteland close to the perimeter fence, was to reassure workers that there was a fast way out should one ever be needed. But what it also provided was a single pathway from the reactor to the outside world. It was, in one sense, the barrel of a gun. All it needed was to be unblocked.

Nobody noticed Ravi as he strolled over to the emergency door, and even if they had, they wouldn’t have remarked on it. Everyone had their own worksheet. They would assume he was just following his. He opened the inner door—a solid metal plate—and let himself into the corridor. This was identical to the one he had used to enter, the same size and shape as a passageway in an underground train station—only without the advertisements. About halfway along, there was a control panel fixed high up in the wall. Standing on tiptoe, Ravi unscrewed it, using one of the few real tools he had brought with him. Inside, there was a complicated mass of circuitry, but he knew exactly what to do. He cut two wires, took one of them, and attached it to a third. It was quite easy, really. The exit door slid open in front of him, revealing a patch of blue sky on the other side of another wire fence. He felt the sluggish air roll in. Somewhere, perhaps in the control room, someone would notice what had happened. Even now a light might be blinking on one of the consoles. But it would take a while before anyone came to investigate and by then it would be too late.

Ravi went back into the reactor chamber and over to the nearest of the four reactor coolant pumps. This was the only way that wide-scale sabotage was possible. What he was aiming for was known in the nuclear industry as a LOCA—a Loss of Coolant Accident. It was a LOCA that had caused the catastrophe at Chernobyl in the former Soviet Union and had almost done the same at Three Mile Island in Pennsylvania. The pump was locked in its cage, but Ravi had the key. That was one of the reasons he had been chosen for this job. The right man in the right place.

He stopped in front of the cylindrical wall, which rose more than sixty feet into the air. He could hear the machinery inside. The noise was constant and deafening. His mouth was dry now, thinking about what he was about to do. Was he insane? Suppose they traced this back to him? But then his mind drifted to all that money, to his wife, to the life they could finally lead. His family was not in Chennai today. He had sent them to friends in Bangalore. They would be safe. He was doing this for them. He had to do this for them.

For a few brief seconds greed and fear hung in the balance, and then the scale tipped. He knelt down and placed the toolbox against the metal casing, opened it and removed the top shelf. The inside was almost filled with the bulk of the plastic explosive, yet there was just enough room for a digital display showing ten minutes, a tangle of wires, and a switch.

Ten minutes. That would be more than enough time to leave the chamber before the bomb went off. If anyone questioned him, he would say he needed to use the toilet. He would exit the same way he had come in, and once he was on the other side of the air lock, he would be safe. After the blast, there would be panic, alarms, a well-rehearsed evacuation, radiation suits for everyone. He would simply join the crowds and make his way out. They would never be able to trace the bomb to him. There wouldn’t be any evidence at all.

People might die. People he knew. Could he really do this?

The switch was right there in front of him. So small. All he had to do was flick it and the countdown would begin.

Ravi Chandra took a deep breath. He reached out with a single finger. He pressed the switch.

It was the last thing he did in his life. The men from the street corner had lied to him. There was no ten-minute delay. When he activated the bomb, it went off immediately, almost vaporizing him. Ravi was dead so quickly that he never even knew that he had been betrayed, that his wife was now a widow and that his children would never meet Mickey Mouse. Nor did he see the effect of what he had done.

Exactly as planned, the bomb tore a hole in the side of the coolant pump, smashing the rotors. There was a hideous metallic grinding as the entire thing tore itself apart. One of the other plant operators—the same man who had been chatting about cricket just a few minutes ago—was killed instantly, thrown off his feet and into the reactor pit. The other engineers in the chamber froze, their eyes filled with horror as they saw what was happening, then scattered, diving for cover. They were too late. There was another explosion and suddenly the air was filled with shrapnel, spinning fragments of metal and machinery that had been turned into vicious missiles. The two closest men were cut to pieces. The others turned to run for the air lock.

None of them made it. Alarms were already sounding, lights flashing, and as the machinery disintegrated, it seemed that everything in the chamber had been slowed down, turned into a black-and-red hell. A cable whipped down, trailing sparks. There were three more explosions, pipes wrenching themselves free, fireballs spinning outward, and then a roar as burning steam came rushing out like an express train, filling the chamber. The worst had happened. Jagged knives of broken metal had smashed open the pipes, and although the reactor was already closing down, there were still several tons of radioactive steam with nowhere to go. One man was caught in the full blast and disappeared with a single hideous scream.

The steam thundered out, filling the entire chamber. Normally, the walls and the dome would have contained it. But Ravi Chandra, in almost the last act of his life, had opened the emergency air lock. Like some alien stampede, the steam found it and rushed through, out into the open air. All over the Jowada power station, systems were being shut down, corridors emptied, safety measures put into place.

But it was already too late.

The people of Chennai saw a huge plume of white smoke rise up into the air. They heard the alarms. Already, workers at Jowada were calling their relatives in the city, warning them to get out. The panic began at once. More than a million men, women, and children dropped what they were doing and tried to find a way through traffic that had come to a complete standstill. Fights broke out. There were collisions and smashups at a dozen different junctions and traffic lights. But it had all happened too quickly, and not a single person would have actually made it out of the city before the radioactive cloud, blown by a southerly wind, fell onto them.

The story appeared that night on television news all around the world.

It was estimated that at least a hundred people died in the one hour following the explosion. Of course, there had been casualties within the Jowada power station itself, but far more people were killed in the madness to get out of Chennai. By the following morning, the newspaper headlines were calling it “A NUCLEAR NIGHTMARE”—in capital letters, of course. The Indian authorities were adamant that the steam cloud would have contained only low-level radiation and that there was no need for panic, but there were just as many experts who disagreed.

Twenty-four hours later, an appeal was made to help the people of Chennai. Further casualties were being reported. Homes and shops had been looted. There were still riots in the streets and the army had been called in to restore order. The hospitals were full of desperate people. One British charity—it called itself First Aid—came forward with a comprehensive plan to distribute food, blankets, and, most important of all, potassium iodate tablets for every one of the eight million people of Chennai to counter possible radiation sickness.

As always, the world’s people were unfailing in their generosity, and by the end of the week First Aid had raised over two million dollars.

Of course, if the disaster had been any greater, they would have raised much, much more.