Shivvi Tan Fook was Greencorps’ most experienced diver. Recruited from the streets of Kuala Lumpur, she had, in addition to her innate underwater skills, become a hardy survivor and a first-class thief. Rising through the ranks of the multinational operation, she developed a reputation for ruthlessness that brought her to the attention of Nathaniel Flowerdew. Between them they ran the Greencorps operation in the Nigerian delta, siding with the government against the warring ethnic groups and united in their greed and determination. Shivvi ran a team of fearless women divers who became her gang, her protectors. Shivvi and Flowerdew had both been involved in the disastrous drilling operation that had cost many lives; he was the instigator, she its executor. Even in Lagos, the oil-pollution capital of the world, with three hundred spills a year, it had caused outrage.

To no one’s great surprise, Greencorps had protected their senior man; Shivvi had gone to prison, and her diving sisterhood was disbanded.

Now, as she lowered herself into the depths of the Woodingdean Well, she was motivated by the desire for revenge. Revenge against the company that had left her to rot; she had already taken her revenge against the man who should have been in that prison—the man who had told her about the 126 and about Itchingham Lofte. She’d had the idea of enrolling as a student in order to get the information from the boy, and she might have succeeded if it hadn’t been for Lucy Cavendish. Now, with Flowerdew gone, she could help herself to the wealth and power she deserved.

At three hundred feet down, she slowed her descent. The horizontal tunnel that led off the main shaft was close now, and she needed to be ready. According to Itch, the water started at the bottom of this drop, but her headlamps picked out nothing but bricks, moss, and sludge. She angled her head so that the powerful beams were shining downward: no water. Eighty feet from the bottom her rope ran out, and she had to use the metal ladder. Shivvi could now see that the bottom of the shaft was covered in mud and broken bricks but was dry. She was so absorbed in looking for water that she nearly missed a run of five broken rungs, snapped through the middle like twigs. She stopped just in time and, guessing the drop was no more than twelve feet, unhooked the duffle bag and other ropes, letting them fall to the bottom. They landed with a thud, and Shivvi risked a jump. She needed to avoid snagging her delicate Neoprene diving suit, but she was in a hurry. Her DANGER! HIGH EXPLOSIVES! notice by the security doors would only work for a while. She needed to be back up before the school day proper started.

She landed cleanly, her heart racing. Where was the water? As she straightened, she found she was staring down a large tunnel that ran off horizontally from the main shaft. Circular and about ten feet in diameter, it was thick with sludge and refuse. Pieces of wood and crumbled bricks were strewn across Shivvi’s path as she stepped slowly into the shaft. Her headlamps picked out green mosses like wallpaper covering the entire tunnel—but it was all dry.

“Itch, you son of a gun. You’ve actually made this a whole lot easier than you thought….” Shivvi had been expecting to swim along this section and then prepare for the toughest dive of her life, down the remaining eight hundred and eighty-five feet. She had never done more than six hundred, and when she’d discarded some of her equipment because of the size of the well opening, she had wondered if the dive was even possible. But with every step the realization took hold that the sodium explosion had cracked the walls somewhere and the water had seeped away.

The horizontal shaft was around thirty feet long, then it dropped out of sight. How much water was left? Might it be dry all the way to the bottom; if so, did she have the equipment for the climb? As she approached the edge, she sensed moisture in the air, and the smell of old, dank vegetation. There was water down there somewhere.

Shivvi had dived in extreme conditions before, but never anything like this. More than four hundred feet below the ground, she stood at the mouth of the circular shaft, looking down into the void. Her lamps were picking up dark reflections far, far below her, and she threw a piece of broken brick over the edge. Several seconds passed before a splash was heard—the water was there all right, but three hundred feet away? Four hundred? The rungs continued down this shaft, but as Itch had never come this far she didn’t know how useful they would still be.

She had brought her diving sled with her, which could help get her to a predetermined depth, but she was beginning to think that it would be useless here. This would be a climb and a dive; she just wasn’t sure how much climbing and how much diving were involved.

A moment’s hesitation … How much did she really want this? Was it worth risking everything for? She thought of the Ikoyi Prison and the daily humiliations she had faced there. She thought of the life Flowerdew had enjoyed while she languished. And then she thought of the unparalleled power and wealth that lay in front of her. She was here first, and it was there for the taking.

With the ropes around her and her fins tied around her neck, Shivvi Tan Fook stepped down onto the first rung.

Walking swiftly toward the Fitzherbert School, Flowerdew, Loya, and Voss were looking at their text messages. They had all received the news from their driver, now parked a few streets away.

Police arriving from everywhere.

“They can’t be here for us, but it’s not good news.” Flowerdew was frowning.

“Maybe someone has recognized you, Dr. Flowerdew?” suggested Voss.

“Maybe. But unlikely,” he said. “There hasn’t been a photo of me on the news or anything. No, it’s Shivvi, I’m sure of it. She must have found the location of the rocks after all. And, in her own stupid, bumbling way, has been found out. Damn it to hell.” He kicked the hubcap of a nearby car.

“Let’s not get overexcited,” Loya said.

“I thought that’s what you Latin types did all the time,” snapped Flowerdew. “I’ll kick what I want.”

The two agents exchanged glances, and Loya shook his head, urging silence.

Flowerdew was striding up the school drive. “Either Shivvi is on her way,” he muttered, “and they have arranged a welcome party, or … she’s already here.”

“And diving?” asked Voss, following close behind.

“It’s what she does,” replied Flowerdew. “That and losing.”

“Let’s find her,” said Voss as they hurried up the steps. “And remember—we say we are from the hotel group Mondo if we are challenged. Assessing development …”

Shivvi wasn’t sure how deep she was when she came to the water. She had stepped and sometimes slithered her way down the rungs built into the well wall by its nineteenth-century constructors. She looked up—she was maybe three hundred feet down from the horizontal shaft, and the black, impenetrable water was now at her feet. She adjusted the lights on her helmet with one hand as she fitted her fins with the other. The rubber foot pockets slipped over her feet, the long blades pointing down toward the water.

She continued the pre-dive breathing routine that she had started in the car. She was in a hurry, but if she got this wrong she could die. She had done this all her life, and it came naturally to her. She took big breaths from deep in her stomach, focusing first on the exhale, then on the inhale. She emptied her lungs completely, then filled them to capacity. After two minutes she put on her black silicone mask and shrugged the empty black duffle onto her shoulders.

Calm. Steady. Focus. One enormous breath.

She slipped into the water.

The cold was shocking. Even though she was prepared for it, and her suit was the finest money could buy, it still hit her like a punch in the face. She knew that the cold would channel most of her available oxygen to her heart and brain, also that the clock was ticking. Her record was nine minutes and forty seconds, but that was in warm water, with no baggage. This time the water was freezing and she would have to carry the rocks back to the surface.

She pushed down. Her lights penetrated only a short distance in the total blackness of the well water, but just far enough to see each row of bricks as she descended. Her fins cut huge swathes through the water, giving great thrust with little effort, her legs staying as straight as possible and kicking once per second. She was streamlined, her chin tucked into her chest as she concentrated on the rows of passing bricks. Instinctively, she emptied her mind.

Bricks … blackness … kick. Bricks … blackness … kick.

She felt the familiar chest pain that stayed with her for the first couple of hundred feet ease off, only to be replaced by a constant pain between her ears. As she sped lower, she used air held in her mouth and throat to feed into her cheeks, using them as an air reserve. Moving her tongue, neck, and jaw, she moved the air into airspaces in her sinuses and ears; here the pressure wouldn’t compress the air as much as in her chest. It was a trick called mouthfill, which she had learned as a teenager, diving in the South China Sea. Without it she would have had to return to the surface by now.

Bricks … blackness … kick.

Shivvi was feeling dizzy now; her eyesight blurred; she had to fight away the stupor. Bricks … blackness … kick.

How deep was she? Surely the bottom was not far away; she noticed that the well walls were crumbling and dissolving.

Bricks … blackness … kick.

Her lungs were being squeezed down to the size of fists and the pain was overwhelming. She hadn’t experienced pressure on her eardrums like this before, but she stuck to her routine. Lights were popping in her eyes, and finally her rhythm faltered.

The first thought of failure entered her mind now: her chest wall was on the point of collapse; her lungs would be filling with fluid, mostly blood. Getting back to the surface—for her, always the start of the dive, where the real work began—was going to be a mighty struggle.

She had given herself just three more kicks when she hit the bottom. It happened very quickly—she had clearly been falling faster than she realized—and suddenly she was in the mud, surrounded by old rusty winch machinery. Terrified of tearing her suit, she floated back up a few feet and, with all the control she could muster, pushed down again. This time the well bottom emerged slowly, and she saw wooden planks, rusted chains, and a large circular cable. And, there, half submerged in mud and slime, amid the tattered remains of an old backpack, a polyethylene and lead radiation box.

In the lab and on his knees, Itch pulled desperately at the copper pipe that held him tightly. He knew he had only seconds before he would be overcome by the toxic cloud that was billowing around him. At first the copper was unyielding, but as he tugged, he felt it soften. With a new burst of energy, he pulled against the pipe, but he got the angle wrong and the handcuff slipped, shooting away from the corroding reaction. Frantic now, his chest beginning to burn and the heat from the reaction adding to his discomfort, he dragged the cuff back along the pipe until he felt it dip into the reacting metal. If his eyes had been open he would have seen the fumes enveloping his head and circle around the lab. With another powerful heave, he felt the pipe suddenly give way. Water shot everywhere and he fell backward, gasping.

He opened his eyes. The pipe had ruptured and the handcuff had been pulled through the broken copper, but the fumes were everywhere: as he breathed in, his lungs burned and he choked. Spinning around, then slipping in the water, Itch sprinted away from the lethal haze that had settled above the sink.

He stood in the corridor outside the science lab, wheezing and gasping for air. He was coughing and retching, and his eyes were stinging, but he knew he’d gotten away with it. A broken finger, a gouged hand and some inhaled NO₂—but he’d escaped. He wiped his eyes with his sleeve, the handcuffs banging against his chin.

You’re fine—now find Jack.

He ran past the metalshop and woodshop rooms, and came to the well opening. Remembering Shivvi’s threat to Jack, he tiptoed onto the metal plate and peered down.

Jack was about fifteen rungs down and, seeing the light change above her, she glanced up. She looked exhausted, her face tear-streaked. Itch put his finger to his lips and Jack saw the cuffs dangling from his wrist. She beamed, the relief lighting up her face.

“She’s down there,” she said softly. “Don’t know where exactly. But she’s been gone a while.”

“Can you get out?” Itch whispered.

Jack showed him the cuffs. “How did you get free of yours?” she asked.

“Nitric acid. But it’s no use down there—the fumes would kill you before you could get out.”

Jack suddenly saw Itch’s head whip around.

“Jack, there’s someone coming!” he said, and disappeared.

She tensed, and then saw Itch’s head above her again. “We’re gonna be fine,” he said quickly, and was gone.

The noise was coming from behind the new security doors that Shivvi had shut: first a rattling of the handle, then pushing, followed by fists banging. Itch could hear voices, indistinct but urgent. He stood there, frozen in indecision: if they were teachers, their ordeal could be over; if they were police they’d be safe, but the rocks would have to be handed over. That, he quickly concluded, would be better than Shivvi escaping with them, and he ran toward the double doors. He was about to call out when he felt the blood drain from his face and his legs go weak.

On the other side of the door he heard a voice shouting, “Come on—surely you’ve got something to get these doors open with!” and he knew he and Jack were in even more trouble.

It was Nathaniel Flowerdew.