The Gods of Atlantis

PART 1
1

South-eastern Black Sea, present day

‘Jack, you’re not going to believe what I’ve just found. It’s gold. Solid gold.’

Jack Howard twisted round and stared at the orange glow of the headlamp from the other diver below him, the form almost completely obscured by the swirling black cloud of sediment that filled the tunnel. He dumped air from his buoyancy compensator and dropped down, flexing his knees to prevent his fins from scraping the jagged lava wall, then angled sideways to avoid becoming entangled in the cable that snaked up to the submersible on the sea floor above them. He injected a blast of air into his suit to reacquire neutral buoyancy, catching a glimpse of Costas’ face through his visor as he finned sideways to let Jack take his place. Costas was staring intently at the tunnel wall in front of him, aiming his headlamp at one spot. Jack followed his gaze, edging forward, keeping his breathing shallow to maintain his depth in the water, staring into the swirl of sediment. Slowly the particles settled, and he began to make out the wall beyond. He could see the twisted black lava from the eruption five years ago, its friable surface broken and exposed by the boring drill that had dug through the solidified flow the day before to create the tunnel. But then he saw something different, embedded in the lava, a smooth rock surface cracked and mottled by the searing heat of the eruption. He peered at the polished surface, his heart suddenly pounding with excitement. There was no doubt about it. He was looking at a pillar, on some kind of plinth. A pillar carved by human hands.

‘Yes.’ He punched his fist in the water, then turned to Costas, speaking into his intercom. ‘I’d begun to wonder whether this place really existed at all, or if it was just a figment of our imagination.’ He turned back to the pillar, seeing where the plinth had been carved out of the natural tufa. He had a flashback to the moment he and Costas had first seen archaeological remains at this site five years ago from the Aquapod submersibles, watching in awe as the veils of silt dropped and the walls and roofs of the ancient city appeared, the most exhilarating moment to that date in his career as an underwater archaeologist. Revisiting scenes of past triumph was sometimes a strange experience, recalling emotions and high drama long gone, but this time it was different, like entering a completely new world. The volcanic eruption that had engulfed the site and forced them to leave five years ago had created a totally unfamiliar environment, a seascape as barren and devoid of life as the surface of the moon. He turned to Costas. ‘This is the first proof we’ve had it was all real. You’re right. It’s archaeological gold.’

Costas tapped his shoulder, and aimed his headlamp midway up the wall above the plinth. ‘Jack, I meant real gold. Have another look.’

Jack followed Costas’ beam and took a deep breath, holding it for a moment to rise half a metre in the water. The beam lit up a final swirl of volcanic particles that obscured the pillar, and Jack put out his hand and wafted them away. He let his hand drop, and then gasped in amazement. ‘Well I’ll be damned,’ he whispered.

‘See what I mean?’

Jack stared, wondering whether his imagination was playing tricks on him. The object in front of him was remarkably similar to one they had found five years ago, the object that had first led them to this place. He saw the reflected shimmer of gold on the inside of his visor, and he closed his eyes for a moment, half expecting it to be a phantasm, to be gone when he opened them. But it was still there, a golden disc about a hand’s breadth across embedded in the pillar, the sheen of gold almost blinding him in the reflected glare of the headlamp. He reached out and carefully pressed the fingers of his glove against it, feeling the solidity. It was real. He felt the adrenalin course through him, and turned and grinned at Costas. ‘Now I really believe it.’

‘That’s the Atlantis symbol, isn’t it?’

Atlantis. It was the first time either of them had uttered the word since leaving Seaquest II in the submersible two hours before; as if to say it would risk the site closing up on them again. Jack stared, searching with his eyes, seeing nothing but the golden reflection. ‘Where are you looking?’

Costas turned his head to move his beam away. ‘Use your own headlamp, angled down, low beam. You should get more shadow.’

Jack reached up to his helmet and activated the twin halogen lamps on either side, then ramped them down. Suddenly a symbol appeared on the disc, its lines deeply impressed into the gold. He stared in astonishment, his mind racing back to the extraordinary events of five years ago, to the excavation of a Bronze Age wreck in the Aegean Sea at the start of their quest. They had found a golden disc with this symbol, alongside other symbols Jack had recognized from an ancient pottery disc found a century before at the Minoan site of Phaistos in Crete. The Phaistos symbols had baffled archaeologists for generations, but the disc from the wreck contained parallel symbols in the Minoan Linear script, an early form of Greek, which allowed the Phaistos symbols to be translated.

What they had revealed was astounding, the greatest revelation from an ancient text in the history of archaeology. One word had stood out, a word that had bedevilled archaeologists since time immemorial, a word spelled out in the syllabic script of the Minoans and represented by the symbol in front of Jack now: Atlantis. That had been remarkable enough, but then his colleague Maurice Hiebermeyer had made another discovery deep in the Egyptian desert, a fragment of papyrus showing that the story of Atlantis told by the Greek philosopher Plato had not been a myth but was based on hard reality, on an account given to a Greek traveller by an Egyptian priest who had inherited secret knowledge stretching back thousands of years before the first pharaohs. Together the papyrus and the disc contained clues that had brought Jack and his team to the south-eastern corner of the Black Sea, searching a shoreline submerged when the Mediterranean had cascaded over a land bridge at the present-day Bosporus and filled the Black Sea basin, the last and most catastrophic event in the sea-level rise caused by the great melt at the end of the Ice Age twelve thousand years ago. For Jack, it had been the perfect archaeological quest, a marriage of textual clues, hard science and intuition, and it had brought together all the skills of his team. They had revealed nothing short of the most dramatic archaeological site ever discovered, surrounding the twin peaks of a partly submerged volcano. It had been a spectacular vision of human ingenuity and achievement at the beginning of the Neolithic, when people had built monuments that equalled those of the Egyptians and the Sumerians and the Mesoamericans thousands of years later.

Jack traced his glove over the symbol on the disc, up the central axis to where two symmetrical patterns extended outwards like garden rakes, each terminating in a series of parallel lines. The text on the Phaistos disc had instructed them to follow the shape of the eagle with outstretched wings, and they had realized that the symbol was also a map, a plan of the submerged tunnels and chambers they had discovered under the peak of the volcano. Five years ago they had passed through extraordinary wonders: a huge chamber full of ancient cave paintings of the Ice Age, then a tunnel with carvings showing latter-day priests of Atlantis with conical hats, and then the holy of holies, the place where the tunnel ahead of them now might be leading. Yet that chamber with its huge statue of a mother goddess had been freshly carved shortly before the flood, and Jack was convinced that somewhere inside the tunnels and chambers lay other secrets, something that would link the holy of holies and the priests with those ancestral images from the Ice Age: perhaps an inner sanctum that would reveal how the belief system of the Ice Age hunter-gatherers had transformed into a religion of priests and gods and worship. The most likely location, the complex of tunnels ahead of them, was a place they had only just begun to explore five years ago when the North Anatolian Fault had shuddered and the volcano surged to life again, forcing them away from the site seemingly forever.

Jack pressed his hand against the surface of the disc, wishing he could remove his glove and feel it against his skin. He had found gold before: gleaming coins of the Roman emperors, dazzling cups and jewellery on the Bronze Age wreck, gold fit for a king. But this disc was extraordinarily old, at least as old as the flooding of Atlantis more than seven thousand years ago. That was three thousand years before the earliest site elsewhere to produce worked gold, at Varna in Bulgaria. The gold in the disc could have come here with the first hunter-gatherers who had sought shelter in the caves on the slopes of the volcano during the Ice Age, who had painted the rock with images of mammoths and fearsome lions and leopards: a band of humans of precocious intellect and vision who had travelled south from the retreating glaciers with their most precious belongings. Their talent with metals was clear from the finds five years ago, their ability to collect and work copper and then to make an alloy to produce bronze, thousands of years before bronze technology re-emerged and became widespread in the ancient world. They could have brought the gold with them from the nearest rich source, the gold-bearing streams of the Caucasus Mountains to the east, laying woolly mammoth skins in the water and collecting the precious flecks just as the Greek myths had Jason and the Argonauts do with the Golden Fleece. And they could have smelted and fashioned the gold into a disc bearing their sacred symbol, perhaps at the time they were transforming their world – moving beyond the natural caves in the volcano to cutting their own passageways and chambers in the rock, then fashioning mud-brick and lime and volcanic ash into the walls of houses, creating the world’s first civilization.

To Jack, the golden disc represented everything that was fascinating about this place: the symbol of a people on the cusp of the greatest revolution in human history, a symbol that allowed them to look forward to a new world and yet also back to the time of their ancestors. He wanted to feel what they had felt, to see the world as they had seen it, to look far back in prehistory to the time before the memory of the deep past had become clouded by the foundation myths that followed the first cities and the first dynasties; and he wanted to look forward to where these people were going, to understand what motivated them as they poured all their energy into creating this place and then fleeing the oncoming flood. If he could see those things, then he would have found the greatest treasure of this place. He wanted to discover their past. Above all, he wanted to find out about their beliefs, how these people saw their existence at the dawn of modern religion. He wanted to find the gods of Atlantis.

Costas tapped Jack’s helmet. ‘You happy?’

Jack drew his eyes away from the symbol and looked at Costas, his form now visible as the sediment cleared. Beneath a tattered boiler suit filled with tools, Costas was completely encased in white, like an astronaut. His helmet bore the anchor logo of the International Maritime University, partly obscured by a laser range-finding device that he had spirited up in the engineering department, one of numerous gadgets that always festooned him when he went diving. Underneath the white outer layer they were both wearing e-suits, Kevlar-reinforced drysuits with integrated buoyancy systems, back-mounted oxygen rebreathers and dive computers with readouts visible inside their helmets. But the famed environmental resilience of the e-suit did not extend to diving in near-boiling water inside an active volcano, so they were entirely encased in thermal protection developed at IMU from the latest NASA and Russian spacesuit technology. Jack had to remind himself that they were not inside some lunar simulator, but under the Black Sea off Turkey, more than thirty metres below a solidified lava flow and heading for a place that made outer space seem distinctly congenial by comparison.

He tapped the intercom on the side of his helmet. ‘Happier now I know we’re on target. Lucky that pillar wasn’t crunched by the borer.’

‘I was driving it, remember? Rule number one. Never trash the archaeology.’

‘You mean you got lucky.’

‘We used the 3-D terrain map of the site from five years ago, and put the borer dead on the entrance to the chamber leading to the holy of holies.’

‘I’ve lost all sense of direction. My compass has gone haywire.’

‘Did Lanowski mention the magnetic anomaly?’ Costas said. ‘We noticed it yesterday when we did a magnetometer run over the site. The readouts showed some pretty spectacular spikes, centring over the likely location of the magma chamber. The Turkish geological survey guy with us said he’d recorded a similar anomaly at several other places along the North Anatolian Fault, though nowhere as spectacular as here. You get anomalies like this at a few other places in the world where an upsurge in magma has a localized effect on the earth’s magnetic field – along the Puerto Rico Fault in the north Caribbean, for instance. The guy said there’s a lot of variation in how magnetic materials react to these field changes, but they’d noticed that meteoritic iron is the most dramatic. Several samples they had from one meteorite impact site in Siberia felt twice as heavy as normal at one place along the North Anatolian Fault where they tried them, and he reckoned it might even be more marked here.’

‘Sounds like fodder for the fringe theorists,’ Jack replied. ‘The people who still think Atlantis could only have been built by extraterrestrials. The truth is, everything we saw here is paralleled elsewhere in early sites, only on a lesser scale. And we only have to look at the Egyptian pyramids or Stonehenge to see that doing things on a colossal scale was never as much of a problem in the past as the fringe theorists seem to believe.’

‘Man makes himself,’ Costas said. ‘Isn’t that the famous Jack Howard byline? Everything he builds, and all his ideas, come from within.’

‘And then he sometimes unmakes himself,’ Jack said. ‘That’s what I really want to find out here, whether these people were the first to take hold of their own destiny and see the potential within themselves, and the danger. That’s what seems to have fascinated Plato about Atlantis when he used the story to warn the Athenians about hubris, about flying too close to the sun. Call it the Icarus factor.’

‘My objective is to see whether little baby ROV will work inside a volcano,’ Costas said cheerfully, patting his oversized torso. The Michelin Man effect of the suit was compounded by the cargo Costas was carrying: a miniature remote-operated vehicle the size of a toaster, which he had zipped up inside a protective bag on his chest, like a kangaroo with a pouch. Costas was one of the world’s leading submersibles experts, and his passion was miniaturized ROVs, the focus of endless happy evenings tinkering in the engineering complex of IMU’s main campus at Cornwall in south-west England.

‘So how’s Little Joey doing?’ Jack enquired.

Costas held up the tethering cable that hooked the ROV’s battery to the submersible at the entrance to the tunnel, and checked a monitor on his wrist. ‘Only a few minutes more now.’

Jack turned again and stared at the golden disc. ‘Odd that we didn’t notice this pillar the last time we came this way.’

‘Jack, we were a little preoccupied, remember? You were having a gun battle, and I was about to be executed by a Kazakh warlord who was going to hurl me into the magma chamber.’

Jack stared ahead pensively, casting his mind back five years. There had been a dark side to the discovery of Atlantis, and a cost to himself personally that had preyed on him since returning here. Five years ago they had made another discovery, one that had turned the archaeological hunt into a modern-day race against time. At the end of the Cold War, a renegade Russian captain had taken his submarine full of nuclear warheads towards a secret rendezvous with a buyer in the Republic of Georgia, but had struck the uncharted submerged flank of the volcano and sunk. When Jack and his IMU team had stumbled across the submarine, the middleman had returned with a vengeance, seeking his merchandise. In the ensuing battle, the original Seaquest had been sunk and they had lost one of their team, Peter Howe, the IMU security chief. Peter had been a close friend of Jack’s from their schooldays and time in British Special Forces, and had been persuaded to join IMU when Jack had set it up soon after completing his doctorate at Cambridge. In the five years since his death, Jack had been driven by a feeling of responsibility to the dream he had shared with the original few – with Peter, with Costas, with Maurice Hiebermeyer – a dream that had seen them chart discoveries far more extraordinary than they could ever have imagined when he had founded IMU. But there was still a shadow over this place: the discovery of Atlantis had come at a price, one he never wanted to have to pay again.

Costas peered at him. ‘We could call it a day, Jack. This is going to be a dangerous dive, and we’ve got a spectacular result now with that disc. It’s hardly as if IMU activities have been out of the spotlight for the last five years, but when you decide the time is right to reveal this to the media, it’ll boost public interest big time. And we’re not even supposed to be here at all. It’s your call.’

Jack took a deep breath. Costas was right. They had returned to Atlantis on a wing and a prayer. Two weeks ago they had been in Seaquest II off the ancient site of Troy in the northern Aegean Sea, excavating the remains of a galley from the time of the Trojan Wars in the late second millennium BC. At the citadel of Troy itself, his oldest friend Maurice Hiebermeyer and their Cambridge professor James Dillen had been in charge of clearing an extraordinary underground chamber they had found beneath the ancient palace, searching for clues to support Jack’s theory that Troy had been founded at the time of the exodus from Atlantis four thousand years before the Trojan War; that it was a staging post for the diaspora of people who had taken their language and knowledge of farming south and west across the Mediterranean at the dawn of civilization.

At Troy, his mind had never been far from Atlantis, only a few hundred miles east of the Bosporus in the Black Sea, but the chances of a return had seemed remote. Then, two weeks ago, the Turkish and Georgian surveillance team who monitored the Atlantis site had requested IMU assistance in boring a sample shaft into the volcano. Several months previously they had recorded a fall-off in seismic activity, and for the first time in five years a limited intervention for geological purposes seemed feasible, though it was still deemed too risky for diving. The main concern was to understand better the seismic characteristics of the North Anatolian Fault, the huge rent in the earth’s crust that ran west under the southern shore of the Black Sea to the Bosporus Strait, threatening Istanbul. Jack had seized on the chance and offered Seaquest II, which had the right sub-sea boring equipment and could sail immediately from the excavation site at Troy. Costas and their brilliant if quirky engineering genius Jacob Lanowski had spent several sleepless nights downloading all the survey data from five years ago so that they could position the boring tunnel exactly where Jack wanted it to go, towards an unexplored entranceway he had seen five years before; at the same time, the priority remained to get the tunnel into the upper magma chamber to satisfy the geologists’ needs.

After heated discussion with Seaquest II ’s captain, Scott Macalister, Jack had won the day, and Macalister had agreed to allow a dive, on the condition that Jack himself arrived from Troy only the day before and then left as soon as he had off-gassed enough nitrogen to allow him to fly. He and Costas had departed that morning in the submersible under cover of darkness, from Seaquest II ’s internal docking bay. It was a covert mission in every sense of the word, and went against many of Jack’s better instincts. The international protocol following the eruption five years before had been to leave the site undisturbed until improved technology and seismic conditions allowed further research, with IMU acting as the overseeing agency and the Turkish navy enforcing a no-dive zone to deter looters. The site was beyond the twelve-mile territorial limit and the protocol was therefore not protected by law, but Jack knew that any attempt openly to dive at the site would upset the agreement and might make the Turkish authorities think twice about continuing IMU’s permit to excavate at Troy. He had weighed it all in his mind over and over again, but he knew that the chance to be where they were now might never come up again in his lifetime. Anything they found would have to be reported as incidental to supposed emergency repair work on the boring equipment, and his own presence in the tunnel – which could only have been for archaeological exploration – kept strictly hushed up.

He turned to Costas. ‘You know my answer. I’ve taken too much of a risk with IMU’s reputation getting here to bail out now. And I want more than gold. I want to find the inner sanctum of Atlantis.’

‘You remember what Macalister said?’

Jack recalled Macalister’s briefing just before they set out in the submersible. Although Jack was archaeological director of IMU, Macalister as captain of Seaquest II had the final say over anything that might affect the safety of his ship and crew, and one of those concerns was holding position over an active sub-sea volcano that might burst forth at any moment. ‘He said don’t push this place. We’ve seen what it can do.’

‘You remember what else he said?’

‘Just the usual.’

‘He said no frigging about. Do not let Jack Howard see something else that intrigues him and disappear off alone down some tunnel. He knows you pretty well, Jack. We go in, we take pictures, we come out. Full stop. He told me if needs be, tie a rope to your ankle.’

‘And you said?’

‘I said nobody ties Jack Howard down. I said I trusted you.’

Jack grinned. ‘Trusted me to do what?’

‘Trusted you to look after me, to look after yourself and to think of your daughter Rebecca and how much she needs her dad, alive and well. Remember what happened six months ago.’

Jack was silent. He remembered all too well. During their search for the treasures of Troy, Rebecca had been kidnapped, the worst forty-eight hours of Jack’s life. It had ended in an explosion of violence that had frightened even Jack, showing him how far he would go to protect his own. It was still unresolved business, with the mastermind behind the kidnapping still at large, but the important thing was that Rebecca was safe and being watched over by the best security people available. She had needed all her friends at IMU afterwards, but she was young enough to feel that it was also a huge adventure, and she had shown a toughness and resolve that proved to Jack that she had inherited a certain ability to look after herself.

‘It was hard enough keeping her from joining us. She’d have been halfway down the tunnel ahead of us by now.’

‘Like father, like daughter.’

‘Anyway, what about Costas Kazantzakis, always stuck down a hole in the seabed fiddling with some malfunctioning gadget, oblivious to the world around him?’

‘My gadgets don’t malfunction. And I don’t fiddle. Anyway, when have I ever let you down?’

Jack grinned through his visor at Costas. ‘Never.’ He lifted his right hand with the palm out, and Costas did the same, pushing them together. ‘Buddies.’

‘Right on.’

Jack turned back to the stone pillar, now clear of silt, with the golden disc reflecting luminously in his headlamp. He flipped up the protective cover of the pod on the front of his helmet and activated the control board on his right wrist, using the pod to take a series of flash photographs and then a video sequence panning up the pillar and focusing on the symbol on the disc. He closed down the visor and pushed himself off from the pillar, hanging in the water alongside Costas in the middle of the tunnel. Costas patted his tool belt, an impressive array of wrenches, jacks and other gear that went with him everywhere, strapped and Velcroed to the tattered grey remains of a boiler suit he wore over his spacesuit, and then gestured at the golden symbol. ‘You don’t want to grab it and bag it?’

Jack shook his head. ‘I think that thing belongs here.’

‘You getting superstitious?’

Jack shook his head again. ‘You remember the golden disc from the shipwreck five years ago, how we realized it was a key to getting into the door in the rock face? It’s just a hunch, but this thing looks like some kind of opening device too. If we can make an obverse of that symbol and use it as a key, then that disc might turn and activate something else. A job for the IMU engineering lab.’

‘I’m on to it. We’ll need a laser scan of that symbol.’

Jack tapped the pod on the front of his helmet. ‘Just done it.’

‘One of my malfunctioning gadgets?’

Jack grinned. ‘Okay. My apologies. It’s just something for the future. We’d need another window in the seismic profile for Macalister to let us down here again.’

‘We’ve waited five years for this window. We can wait again.’

Jack stared ahead. For once he felt more comfortable in a tunnel than in the open sea. Years before, he had nearly lost his life diving in a mineshaft when his cylinder valve had jammed, and had only been saved by Costas buddy-breathing with him to the surface. Since then they had dived together thousands of times, but whenever they were in confined spaces that incident was always lurking just beneath his consciousness, forcing him to keep focused. Yet here the thought of the sea outside was more daunting. Below about a hundred metres depth, the Black Sea was virtually devoid of life, a toxic soup of hydrogen sulphide caused by decaying organic matter with not enough oxygen present. Thousands of metres beyond that, in the abyssal depths, the water was like brine, a legacy of the time before the Atlantis flood when the Black Sea had been cut off from the Mediterranean and had nearly dried up, leaving salt lakes in the deepest reaches. Jack had seen photographs taken by Russian deep-sea probes of ancient wrecks with human bodies encased in salt, sepulchral forms still chained to galleys half swallowed in the brine. And he remembered his escape from the wreck of the first Seaquest five years ago, his desperate climb in the ADSA advanced deep-sea anthropod pressure suit through a bed of volcanic vents spewing plumes of smoke into the darkness. He had sworn he would never dive there again, and he had meant it. He remembered what Macalister had said. Don’t push this place.

He glanced at the digital time readout inside his helmet, and looked at the tether behind Costas. In a few moments they would be ready. He stayed calm, keeping his breathing measured, checking his instruments one last time.

‘I know what you’re thinking,’ Costas said. ‘You’re thinking there’s nothing to worry about. You’ve got the best possible equipment, and the best possible buddy.’

‘Not that. I’m imagining a tropical island, snorkelling on a reef, then cocktails on the shore.’

‘And women?’

‘All you want. Of course, I’m spoken for.’

‘Katya, or Maria?’

Jack coughed. ‘Tough call. So I was thinking of taking Rebecca, for her school holiday. Last chance for some father-daughter bonding. She’ll be having boyfriends soon.’

‘Jeremy’s been seeing her, you know.’

Jack turned to Costas. ‘Jeremy Haverstock? You must be kidding. You must be joking.’

‘He’s a good guy. The best. Helped me a lot with building Little Joey.’ He patted the bulge over his stomach again. ‘Anyway, we all thought you knew.’

‘I thought they were just friends. Colleagues. Rebecca stayed on at Troy to study the pottery, to help Jeremy record the inscriptions.’

‘Rebecca? Spending months recording potsherds? The action girl who makes Lara Croft look like a wimp? I don’t think so.’

‘She’s only seventeen.’

‘Come on, Jack. It’s all part of being a dad. Face reality. Anyway, when?’

‘When what?’

‘When am I going to this tropical paradise?’

‘Well, you’ll need some R and R after this.’

‘You always say that.’

‘I promise.’

The amber light on Costas’ wrist display changed to green. He patted the ROV pouch on his belly. ‘Time to rock and roll.’

‘Let topside know before you unhook the tether.’

Costas tapped the external intercom button on his helmet. ‘Mission control. Do you read me? Over.’

A voice crackled through the intercom. ‘This is Seaquest II. We copy you. Over.’

‘Houston, we are go for a landing.’

There was a pause, and then another voice came on line. ‘This is Macalister. Gentlemen, just remember which planet you’re on. You’re diving in the Black Sea, not landing on the moon. Acknowledge.’

Costas grinned at Jack. ‘Houston, that’s a big wide smile.’

The first voice came on line. ‘Repeat that. We do not copy. Over.’

Costas raised his eyes. ‘Acknowledged. We’re divers, not astronauts. Over.’

Macalister came on again. ‘Be safe. Remember the briefing. We’ll look out for your radio buoy from the submersible in one hour. Over.’

‘Roger that. Little Joey’s all juiced up. We’re going in hot,’ Costas said.

‘Don’t say that,’ Jack replied.

Costas turned to him, grinning through his visor. ‘Afraid of a little lava?’

‘Check your temperature readout. It’s already seventy degrees Celsius. You could poach an egg in this water.’

‘Anything over a hundred and thirty degrees, you abort the mission,’ Macalister said.

‘Roger that. Houston, we are signing off. Over and out.’ Costas reached back and unhooked the tether from his suit, then let it go. They watched it snake and slither out of sight up the tunnel, towards the hazy smudge of green more than thirty metres away that marked their entry point from the sea floor, where they had left the submersible. They were now completely cut off from outside support, dependent entirely upon themselves and their equipment, facing a challenge fraught with as much risk as they had ever faced before. Jack turned and looked into the swirling darkness below them, reducing his headlamp beam so his vision was not dazzled by the reflection of light from particles in the water. He saw the hazy outlines of the tunnel walls ahead, and the blackness beyond. He felt his breathing tighten, felt the apprehension, and then took a deep breath and relaxed as the adrenalin coursed through him. He was in his element, where all his training and ambition had led him, an underwater explorer about to enter the most extraordinary archaeological site ever discovered. Right now, there was no better place in the world to be. Costas turned to him, his visor reflecting an image of Jack like a photograph of an astronaut in space, then gestured down the tunnel. ‘Good to go?’

Jack steeled himself. They were about to dive into a live volcano . He raised his hand, then pointed into the void. ‘Good to go.’