The Gods of Atlantis

3

J ack swam to the edge of the tunnel and looked at the underwater magma lake, watching the yellow-brown haze that seemed to undulate over the lava as plumes of bubbles rose through it and shimmered towards the ceiling of the cavern in the darkness far above. He knew that to swim from the ledge over the lava would be like walking on quicksand, with the rising bubbles pulling on his buoyancy and the plumes acting like sinkholes in the water. Far out in the middle he watched a spectacular geyser of molten rock arch upwards, its surface speckled with bubbles of gas. He turned back, checking the gauge readout inside his helmet. They were eighty-five metres beneath the surface of the Black Sea, at least twenty-five metres below the outer flank of the volcano, and he was down to the final third of the air mixture in his rebreather. He had twenty-five minutes left at this depth, no more, before going on to his reserve supply. There would be no chance of an emergency ascent from this depth to the surface and Seaquest II; their only option was to stick to plan and return up the tunnel to the submersible. Getting to the ancient entranceway and then coming back here would be cutting it fine.

He turned to Costas, who had reached down and opened a Velcroed Kevlar flap on his left thigh, pulling out a tube about the length of his forearm. One end was attached to a spool of what looked like heavy-duty fishing line. He clipped the spool to a carabiner on the chest strap of his rebreather backpack and then twisted the tube, causing a handle like a pistol grip to fold out below. Another twist further up and a metal rod with a point like a harpoon snapped out of the front. He wrapped his right glove around the grip and put his other hand further up the tube. ‘I haven’t had a chance to show you this yet,’ he said.

‘Odd place to go spearfishing,’ Jack said.

‘It’s something I’ve been playing with since we were here five years ago,’ Costas replied, eyeing the rock face ahead of them. ‘You don’t tend to think that getting through submerged caverns would be an issue because you can swim through them, but thinking about volcanic activity made me wonder what it would be like if some force were dragging us down, exerting a pull on buoyancy exactly like those gas eruptions would do now.’

‘Got you,’ Jack exclaimed. ‘It’s a grapple gun.’

Costas pressed his wrist control panel, and Jack saw a thin shaft of light from his helmet where a laser rangefinder penetrated the gloom. ‘Twenty-six metres to that ledge,’ Costas murmured. ‘The grapple spear has a lead core to increase weight and the shaft is as narrow as possible for minimal water resistance, but even so its effective range is only about twelve metres. It’ll go further but you need good force of impact for the head to explode.’

‘Explode?’

‘The first ten centimetres of the shaft contains a joined matrix of rods made of titanium with a magnetic ferrous core. The head impacts the rock and detonates a small C-5 charge, and the rods shoot into every nook and cranny for ten centimetres or so around the point of impact. Then they’re locked tight by an electromagnetic pulse I fire down the wire from the gun.’

‘And then you reuse it?’ Jack pointed across the canyon. ‘We’re going to need two lengths.’

‘Once it’s wedged into the rock and magnetized, it won’t come out. But there’s a second head below the first on the shaft, and you can detach the line from the fired head and put it on the second. It’s a gamble, Jack. The total distance is several metres beyond the specs.’

‘How do we get back?’

‘That entranceway is about five metres higher than we are here. We’ll have to free-swim back, but if we launch ourselves with maximum buoyancy we could swim in an arc and land back here without being pulled down.’

‘Okay. Let’s get going.’

‘Move behind me. This thing fires a substantial black powder cartridge.’ Costas clicked on his laser rangefinder again and aimed at the jagged crevice he had been eyeing on the wall, then pulled the trigger. There was a violent shudder and a jet of bubbles and the spear shot off from the tube, pulling the line behind it. The spool abruptly stopped reeling and Costas was pulled forward, just holding himself in time from being yanked off the ledge over the rising bubbles. He pulled hard on the line, then looked back at Jack. ‘Okay. It’s held.’

‘What’s the drill?’

‘I stay here, you swim along the line. You get there, I swing off this ledge and follow you.’

Jack leaned over the void. ‘That line’s ten metres long, and the lava’s what, eight metres below us? That puts you in the soup.’

‘That’s where you come in. As I swim out as fast as I can from here, you reel in the slack. That way if I’m pulled down, the line will hold me high enough above the lava.’

‘Roger that,’ Jack said, pushing himself off and grasping the line in front of Costas. ‘You secure?’

‘Go for it.’

Jack finned forward over the lava, watching the streaks of red in the cooling lobes and nodules directly below him. At about the halfway point he was suddenly surrounded by a miasma of bubbles escaping from the lava below, a silvery mass that seemed to waft around him, bathing him in refracted light. He lost all points of reference, and seemed to be falling precipitately, a feeling that made him want to let go of the line and spread-eagle himself like a skydiver. His hand jerked on the line and he twisted sideways. It was no illusion; he really had been falling. He began pulling himself along, his buoyancy computer continuously adjusting to compensate for the effect of being dragged down in the vacuum created by the bubbles. He reached the grapple, checked that it was locked securely into a crack and then turned to look for Costas, who had crouched down on the edge of the tunnel opening, holding the line. Jack held on to the rock face with one hand and put his other out in the diver’s okay signal, his forefinger and thumb joined in a circle, and then transferred both hands to the line. He heard Costas’ voice crackling on the intercom through some kind of interference, the broken sounds briefly becoming distinct. ‘You ready?’

Jack wedged his body as much as he could into the rock. ‘Roger that.’

Costas launched himself forward in a slow-motion dive, his bulky suit making him look like an astronaut. As the line went slack, Jack hauled on it, looping it quickly around a rock protrusion behind him. It suddenly went taut as Costas was sucked down by a gas plume and disappeared out of sight. The line went slack again, and for a horrible few seconds as he frantically pulled on it Jack thought that Costas might have impacted with the lava. Then the crackling came on the intercom again, and Costas appeared out of the plume and ascended a few metres below him. He reached the ledge beside Jack, then wedged in an elbow and took the grapple gun out again from his pocket, unhooking the line from the carabiner on his chest and feeding it back into the tube. He glanced at Jack through his visor. ‘That was close.’

‘Your boiler suit looks like glue.’

Costas grunted, reached into the crevice to disengage the line from the grapple, then pressed a control on the tube to re-spool the line and hook it back into the second grapple, ready for firing. He wrapped his hand round the grip again and peered at their objective, the rock-cut platform in front of the ancient entranceway some fifteen metres away. ‘Twice lucky?’

‘Go for it.’

There was a jolt as he fired the device again, and Jack watched the grapple arc over and disappear into a fold in the rock about a metre below the ledge. Costas pulled hard, and the line went rigid. He leaned back and Jack swam over him, taking the line in one hand and kicking out above it. This time he quickly made it to the opposite side and Costas followed, swimming forward while Jack hauled, not bothering to loop the line but letting it drop down below. Costas reached the rock beside him and hung on, breathing heavily on his regulator, then he grasped the line near the grapple and let go of the rock to release the carabiner. As he did so, Jack saw a white expanse of gas billow up below them, and at the same moment the rock holding the grapple broke free under the tension and tumbled off the face, dropping down below Costas into the fomenting mass of bubbles now rising up around them. Jack wedged one hand into the rock and reached down with his other to grab Costas under one arm, holding tight as the plume rose through them. For a split second it seemed as if they were dangling in air, and Jack was holding Costas’ entire weight. Then the plume dispersed above them and Costas hit the manual on his buoyancy control. Jack twisted round and looked up, seeing the carved lintel shape above the doorway, straining to look for the ancient symbols he desperately wanted to see.

Just as he relaxed his hold, there was a jerk and Costas’ arm slipped away. Jack twisted back and saw a horrifying sight. Costas was at least five metres below him, his arms flailing, descending fast. Jack slammed his buoyancy control to dump the air inside his compensator and swam downwards. The chunk of rock with the grapple still inside had pulled Costas down like an anchor, and was now embedded in the lava near the edge of the chamber, sinking in and pulling Costas with it. Jack reached him with only a few metres to spare, pulling his chest strap with one hand and releasing the carabiner with the other, then injecting air into both of their buoyancy compensators. He watched the line snake away and disappear into the molten mass below them, and turned Costas round to face him. ‘You okay?’

Costas was wide-eyed, his visor fogged up around the edges from his exhalation. Jack had a sudden sickening feeling. They had just lost their one lifeline, and they had expended more air than they had bargained for. Costas returned his stare. ‘I think that’s twice very lucky,’ he said hoarsely. ‘Let’s get up there, do what we have to do and get the hell out of here.’

As they swam upwards, Jack turned to look out over the lava lake. A surge was rising in the middle, then moving along as if something were swimming just beneath the surface like some ancient spirit monster. Suddenly the mass rose in a giant bulbous dome and split open, disgorging a huge bubble of gas into the water. A second later there was a blinding flash and Jack could see the pressure waves in the water surging towards them. Costas clung to him, pressing his visor against his. ‘Brace yourself!’ The shock wave pushed them violently towards the rock face, and then they were pulled back again over the lava lake by the implosion. Jack held on to Costas with one hand and finned with all his strength back towards the rock-cut door. He seemed to be getting nowhere, as if this were a bad dream, the door impossibly beyond his reach. Then the sucking force of the implosion miraculously relented, and they came to the ledge below the door.

‘What the hell was that?’ Jack said, panting.

‘Phreatic explosion.’ Costas’ visor fogged up as he struggled to regain breath. ‘It happens on land when lava flows over pockets of water, superheating it. Somehow that big bubble of gas under the surface of the lava must have had the same effect, sucking in water, encasing it and boiling it up.’

Jack stared up at the carved lintel above the doorway in front of them. Costas followed his gaze, panting, then he saw what Jack had seen. ‘Symbols. Ancient writing. Is this what you saw before?’

‘It’s fantastic.’ Above the doorway was the rectilinear Atlantis symbol, with other symbols on either side, familiar from the syllabry they had discovered five years before but not yet translated. They looked freshly carved, as if done just before the flood, and several looked only partly completed. Beneath them Jack could make out other symbols, very eroded and clearly much older, some of them looking as if they had been partly chiselled away. He activated his camera. There was no time for detailed recording now. He was jittery with adrenalin, and checked his computer readout. Fifteen minutes of breathing gas left at this depth. He was conscious that the danger had made the reflective part of his mind shut off in the focus on survival, on dealing with each new threat as they encountered it, and that he needed to maintain an awareness of the bigger picture, of just how close they had come to never leaving this cavern alive. He stared at the entrance. He would need five minutes, just to look. With the lava rising inexorably, it was the last chance before whatever lay inside there was lost forever.

‘Jack, you’ve got a problem.’

‘What is it?’

‘Check your internal temperature readout.’

Jack looked sideways inside his helmet, scanning the digital readout. ‘Twenty-six degrees Celsius. I thought it was getting a little warm. I’ll adjust the thermostat.’

‘Don’t do that yet. Wait till you really need it. You’ll blow the system.’

‘What do you mean?’

‘It must have been the heat when we were close to the lava. You’ve got a leak from your coolant reservoir, Jack. You can’t afford to be that close to extreme heat any more, as you’ll soon have no way of cooling down.’

Jack shut his eyes, trying to control his breathing. For a moment he felt nauseous, a flutter in his stomach, the sickening feeling of the walls closing in. Part of him wanted to swim up and dump his air against the ceiling, to create a pocket where he could rip off his helmet and be free, but he knew that to do so would only be a brief illusion of normality in an air space that would feel far more confined than the water below. He swallowed hard. Keep focused. He sucked on his water tube, then looked into the doorway and tried to ignore the lava, which was rising up the rock face below at an alarming rate. Costas had already unzipped his front pocket and disgorged the ROV, which he was testing like a remote-controlled helicopter. Jack realized where the nickname Little Joey had come from. It looked like a miniature robotic kangaroo, with hind legs, a swivelling video aperture for a head and a tethering cable for a tail, leading to a spool on Costas’ chest. The robot craned its neck around and peered at Jack with its single video eye, and then jetted back to Costas, hovering in the water in front of him. Jack swam ahead to the door entrance, then switched on his helmet lights. ‘I’m going in. Five minutes, no more.’

Costas put a hand on the ROV’s neck. ‘Little Joey will be following you. He can send back remote signals, but I’m keeping him on the tether in this place. If you see anything, hold him like I am and put him on to it. Remember, I’m seeing what he sees on the screen inside my visor. Just point and I’ll drive him forward. Then you come out, pronto.’

Jack stared at the ROV, its single camera eye encased in a sphere of glass. It angled its head around and looked at him, the black lens cap half-down like an eyelid. He realized that he was cocking his own head in the same way, as if they were querying each other. He shook his head in disbelief at what he had just done and looked away. The ROV was not alive. ‘Roger that.’

‘Remember what Macalister said. No disappearing down holes.’ Costas’ voice crackled. ‘That electromagnetic interference is increasing again. There must be a lot of ferrous material in the lava here. I may be out of contact with you.’

Jack surged forward, passing through the entrance and finning down the rock-cut tunnel. After about ten metres the tunnel became a T-junction. Jack stopped and checked his remaining time. Four and a half minutes. It had to be one or the other. The ROV came up alongside him and angled to the right, illuminating the passage. Costas’ voice crackled on the intercom. ‘Jack, give me a confirmation on what you see. I think I’m looking at another entranceway.’

‘That’s an affirmation. But there’s one on the opposite side too.’

‘Little Joey’s pointing the way. Left would take you to the surface of the volcano, now under tons of lava. Right would take you towards the location of that open-air platform we saw five years ago, a more likely place for some kind of sanctuary.’

Jack heard crackling as Costas tried to say more, and then a low hum. Whatever it was that was causing the interference, this place was the epicentre. He had no time to weigh up the options. He swerved right and followed the ROV into the passageway, kicking hard to get beyond it. He swam about ten metres further, then followed the passageway as it veered left. Ahead of him the tunnel was partly blocked with rough-hewn squared stones that looked as if they had been hastily assembled. Whatever it was that had been beyond there on the eve of the flood seven thousand years ago, somebody had wanted it cut off. An aperture still remained, big enough for someone unencumbered to crawl through, but not big enough for a diver with gear. Jack rolled sideways to fit the hole and shoved his head through, his headlamp angled upwards. It was a chamber, maybe eight metres across. He could see jagged protrusions of lava from the eruption five years ago, visible beyond another wall of crude masonry that blocked what must have been the open front of the chamber, clearly a cave in the face of the volcano. He twisted to the left, lying on his back, and saw that the opposite side was natural rock, a wide opening that extended inwards. Big multifaceted crystals of quartz were visible in the wall just to his right. He flicked on his helmet video camera, moving his head from side to side to ensure maximum coverage, then struggled to twist around until he was lying on his front. He strained to raise his head up, angling the lamp as high as he could, then he froze with horror.

He was staring at a human face. It was a skull, embedded in the floor of the chamber. The bone had been plastered over and was partly covered with a rough calcite accretion that must have formed underwater after the flood. One eye socket was open, and the other was filled with plaster and a cowrie shell, as if the skull were staring at him through the slit. Jack instinctively recoiled, his breathing coming in short rasps, and then he forced himself to raise his head higher and look beyond. It wasn’t just one skull. There were dozens of them, all embedded in the floor and facing him, all of them plastered over in the same fashion. The accretion as well as the anoxic conditions of the water must have preserved them. Then he saw another skull lying on its side, unplastered, with the jawbone hanging away, and shapes on the floor covered with accretion. Beside the skull nearest to him was a stone basin about half a metre high on a plinth. He reached out his left arm and put his hand inside, scraping the interior, then pulled his hand away and stared at his glove. It was smeared in a thick, viscous substance that seemed to have lined the bottom of the bowl, some kind of residue. He brought his hand under his headlamp beam and stared at it, his heart pounding. The substance was a deep maroon colour.

He was not only looking at the people of Atlantis. He was touching their blood.

He propped himself up on his elbows, straining his neck up as far as he could. His beam flashed on the interior wall of the cavern. To his astonishment, he saw the shadowy outline of paintings on the rock, ibex, leopards, great horned bulls, faded and ancient. In one part he thought he saw where they had been erased, the rock scrubbed clean. He strained up further, and then he froze again.

Towering above the floor were giant pillars, twenty or more of them, their tops extending outwards in a T-shape. They looked freshly cut, with sharp edges; and had not been hewn out of the living rock but hauled here from somewhere else. The arms were carved with outstretched hands, and other relief carving adorned their sides: swirling abstract forms, parts of human bodies, leopards and bull’s horns, scorpions, a vulture. One swirling circular shape might have been a human face, but he could not be sure. As he looked around, he realized that the outer pillars formed a circle about eight metres across, with pairs of pillars within the circle. His mind reeled. A stone circle. The pillars confronted him like the skulls, ghostly sentinels from the past. Jack felt a shiver down his spine. Were these pillars statues of men, or were they gods?

In a flash, he remembered what he had come here to see.

The birth of the new religion.

The death of the old.

The threshold of a new world order, seven thousand years ago, at the dawn of civilization.

His time had run out.

He struggled backwards, grabbed the ROV and shoved it into the hole, leaving it sitting on its hind legs with the camera aimed inwards. He ripped a small tube out of his sleeve pocket and quickly took a scrape sample from the floor of the chamber. Little Joey’s head turned and eyed him, cocked sideways, and then swivelled back to look into the chamber. Jack disentangled his fins from the tethering line and crouched into a ball, rolling round and extending his legs so that he could fin back along the passage. He pulled hard with his hands at first, anxious not to dislodge the ROV, and then he powered ahead towards the T-junction. As he did so, the low hum and crackle in his intercom suddenly became shouted words. ‘Jack! Get out of there now!’

He surged forward and veered into the main tunnel facing the entrance to the magma chamber, where Costas should have been visible. What he saw instead was an image from hell. A surge of lava was lapping towards him, five metres or more into the tunnel. All his instincts told him to go back, to seek some other way out, but he knew he had to go forward and swim over the lava to where he could now see Costas’ beam shining at him no more than ten metres away.

He finned frantically, following the tethering line for the ROV. After five kicks he was over the lava, almost within touching distance. He was being pushed against the roof of the tunnel, and realized to his horror that the boiling water above the lava was rising and forcing him upwards. He remembered his failing coolant system. He was beginning to overheat. The sweat dripped off his face on to the interior of his visor, and he could see the outside of his suit crinkling and turning brown. He was being cooked alive. Suddenly there was a yank on the tether line and he held on, feeling himself being pulled. He turned upside down and clawed his way along the ceiling, but then remembered his cylinder and air pack. He might survive the Kevlar on the front of his suit being scorched, but not his breathing gear. He turned over again, drew himself up into an upside-down crab crouch and pushed his feet and elbows against the rock, hopping forward a metre or so each time, trying to keep his helmet away from the lava. The sweat in the inside of his visor began to boil like spatters of water on an oven hot ring. He pushed one last time and was free, rocketing up into Costas in a tangle with the tethering line. He was dimly aware of Costas unhooking the line and fumbling with his wrist control panel, and he saw that the thermostat had been turned down to its lowest setting, ten degrees Celsius. Costas spun him round and stared him in the face. ‘There may be enough juice in that thing to give you a burst of cool air before it packs up. Can you feel it?’

Jack felt the sweat drip into the corners of his mouth, and then he sensed the coolness. He opened his eyes, blinking the salt out, then reached with his lips for the water tube and sucked hard, grateful that he had not tried to come out upside down and cooked the water reservoir on his back. He spat out the mouthpiece after a few gulps, then gasped hard for a few moments while Costas looked him over. ‘I don’t see any sign of leakage in your e-suit. But the heat-resistant outer shell and the Kevlar is melted from your elbows and knees. You’re not going anywhere near lava again and surviving it. Which is a good thing, because as of about a minute ago, that option closed on us anyway.’

‘What option?’ Jack gasped. ‘What do you mean?’

‘I mean the option of going back the way we came. The option that would have taken us close to the lava again. Take a look.’

Jack floated free of Costas, kicking a loop of the tether cable away, then looked down. It was a terrifying sight. The lava below them had risen at least five metres in the time since they had exited the tunnel. He suddenly realized what Costas meant. He looked over to the tunnel entrance, where the borer had broken through into the magma chamber, their entry point. A great surge of lava flowed up into it, and then another. He spun around to Costas. ‘What are the options?’

‘When Lanowski and I took the submersible over the volcano, we saw a number of places where gas was escaping into the sea. Mostly they were pinpricks, but there was one really big flow. I took a GPS fix on it and I’ve just been trying to relate that to all the directional data I’ve got from our dive. I think it’s one of those two caverns above us.’

Jack looked directly up, and saw two distinct areas of blackness in the rocky ceiling of the chamber some ten metres overhead. ‘Which one?’

‘We’ll have to take pot luck.’

There was a heave in the water, and Jack looked down. To his horror he saw that the entire lava lake had surged upwards, and a great bulge like a wave was rippling towards them from the far side of the chamber. ‘Up! Now!’ he shouted. He finned hard, remembering to breathe out as he did so, then stopped and flipped round, heading back down. Costas was struggling with the tether cord, which was caught around the strap of one fin. Jack reached behind his breathing pack, whipped out his knife and pulled the serrated edge as hard as he could against the cord, sawing the knife against the metallic cable inside. The cord snapped and he pulled Costas’ foot away, smearing himself with the melting rubber of Costas’ fin. He finned frantically upwards, grabbed the cord at the back of Costas’ pack and yanked it to fill the emergency flotation wings in the shoulders of the e-suit. He exhaled forcefully to avoid an embolism and prayed that Costas was doing the same. The lava surge passed only a few metres below them, and seconds later they hit the ceiling of the chamber, jarring against the lava. Jack still had his knife in his hand, and he stabbed it into Costas’ buoyancy aid to expel the air, watching as the bubbles from the torn fabric disappeared up into the darkness above. Costas pushed off, looking down at the melted remains of his fin, and then at Jack. ‘Phew. That was close.’

Jack felt himself close to boiling point again. He took a slurp of his water, now unpleasantly warm, and looked down. The lava was surging up all round them, rising at a horrifying speed. ‘I think what we’ve got here is a major volcanic event,’ he said hoarsely.

‘No kidding. It’s called an eruption. And with the lava pressing up into this space, the volume of water inside the chamber is decreasing and boiling up. There’ll be a flashpoint and another phreatic explosion and everything will vaporize, including us.’

A lava fountain licked the bottom of the divide between the two caverns. ‘See that?’ Jack said. ‘We haven’t got any choice. It’s going to have to be this cavern.’ He pushed off the wall, and they both began swimming up. Jack glanced at his gauge. They were sixty-five metres below sea level, which put them about ten metres higher than the point on the outside of the volcano where they had left the sub. He looked at Costas. ‘Does that magic program of yours tell us how far away the sub is?’

‘The system’s crashed in the heat. But I think we’ve come in a curve, so not as far as we’ve swum. Maybe fifty metres from here, a bit more.’ They reached the top of the chamber, a jagged ceiling of solidified lava that looked like malformed stalactites, with deep cracks and crevices between. The upper recess was about five metres wide. Costas flicked on both of his headlamp beams and swam a circuit on his back, staring up, before returning to Jack’s position. ‘There are three possibilities. How much air have you got?’

‘Almost on reserve. Fifty-five bar.’

‘Okay. You vent carbon dioxide from your rebreather into one chamber, I’ll do mine in another. You’ve got about ten bar more than me left in your breathing gas, so for the third chamber vent some air straight from your tanks.’

‘Roger that.’ Jack followed Costas to the first hole and pressed the button that vented the accumulated carbon dioxide from his rebreather. They watched the bubbles ascend in the beam of Costas’ headlamps, and Costas peered hard while Jack looked down at the lava surging below them. ‘I can see where the gas is pooling against the ceiling,’ Costas said. ‘Nothing’s escaping.’ They moved to the next spot and repeated the process. An arc of lava shot up in the water to within a few metres of them. Costas looked at Jack. ‘Same story.’

‘You sure?’

‘Yep.’

‘This is it, then.’ They looked at each other, then peered down. Jack realized that the lava was rising with greater speed now because the cavern had narrowed, forcing the molten material upwards. ‘We’ve just run out of time.’ An upwelling of gas enveloped them and they both caught hold of a lava protusion just in time to prevent themselves from falling. They finned together up the last five metres, face to face, until they hit the ceiling. Jack saw something, twisted sideways and switched off his headlamp. It was a patch of green light coming down around a hanging pillar of lava about five metres away. He pulled his way over and peered at it, then looked upwards, his heart pounding. They might make it. He had a sudden thought, and turned to Costas. ‘You got any detonator cord?’

‘Never leave home without it.’ Costas quickly reached down into the Kevlar pocket on the waist of his suit. ‘What’s the plan?’

‘This rock isn’t part of the ceiling, it’s a dislodged chunk of lava that must have been blown up here during the eruption five years ago. You can tell because it’s wedged upwards, not downwards. A little help and it might go.’

Costas clipped the detonator into the two-metre section of cord he was trailing, and wrapped it into gaps around the rock. ‘You ready?’ Jack gave the okay sign and swam back five metres to the other side of the recess, followed seconds later by Costas. ‘Turn your back to it and press your visor against mine.’ Costas held Jack tight. ‘Three. Two. One. Fire in the hole.’ There was a sharp bang, and Jack felt the shock wave ripple against his back; he was thankful for the Kevlar pressure suit. They both turned just as the lava chunk fell in a tumble of smaller pieces, splashing into the molten lava below them and exploding into fiery fragments that quickly melted and sank. Jack pulled Costas over to the hole and they looked up. There was a crack about a metre by half a metre wide, and above that he saw the open ocean.

‘There’s no way we’re getting through that opening with all this gear,’ Costas said.

‘We’ll have to ditch it and swim for the sub.’

‘This is a one-way ticket, Jack.’

‘But you’ll be there waiting for me.’

‘No. You first.’

‘No way,’ Jack said. ‘I need to see that you can get though that hole. You’re wider than me.’ In a few moves he stripped off Costas’ backpack, holding it in front of him with the air hoses still attached. Costas did the same for him, and they both floated under the crack. Jack felt the heat of the water searing into his elbows and knees where the thermal layer of the suit had melted. ‘Okay?’ he said. ‘Relax, take six long, deep breaths, then hyperventilate for four. Give me the okay signal when you’re ready.’ He heard Costas breathe fast and hard and hold his breath, and then saw him put his forefinger and thumb together in the diver’s okay signal. He quickly disengaged the hoses from Costas’ helmet and heaved him upwards, watching him disappear in a welter of bubbles. He breathed in deeply, then looked down. This was not happening. A huge ball of fire was surging towards him, an explosion of lava that would rip right through the crack and erupt on the surface of the volcano. He had no time to hyperventilate. He took one huge breath and held it, then pulled out his hoses. On a second’s impulse, he held the pack down and knocked open the safety release valve on the main tank, causing gas to rip out at high pressure. He held it for as long as it took to rocket through the crack into the sea above the volcano, then he let it spiral away. He finned frantically sideways just as the lava shot up in a geyser behind him, the force of the displaced water pushing him further. Below him the magma chamber imploded, the roof dropping into the space where they had been swimming only minutes before, now a fiery mass of molten lava.

He spun around, disorientated, seeing the plume of red fall back into a slick mass on the seabed. He could see no sign of the submersible, nor of Costas. He sensed the shadow of Seaquest II far above, but ignored it. He would never make it to the surface. Then he saw a yellow smudge down the slope of the volcano. It was the light from the submersible’s lamp array that could be activated externally. Thank God. Costas had made it.

He forced his vision to narrow into a tunnel, to exclude all sense of his surroundings other than his destination. He began to swim hard, ignoring the tightening in his chest, the feeling at the back of his throat that was his body’s first attempt to stop him breathing in water and drowning. He was eighteen metres, maybe fifteen metres away. He could see the submersible clearly now, a yellow cylindrical form about ten metres long, raised above the seabed on retractable legs, allowing divers to enter via a hatch in the floor. He saw Costas beneath it, frantically twisting something. The hatch swung open and Costas pulled himself upwards, his head out of sight, then dropped back down into the water, facing Jack. His helmet was gone, but he was wearing the black safety mask they kept as a backup in a pocket on their legs. Jack was ten metres away now, eight, focusing on Costas’ beckoning hands, trying not to black out. He felt his diaphragm heave upwards as his body counted down the final seconds to unconsciousness. The tunnel darkened, and his limbs felt impossibly heavy. Then he was grabbed and heaved upwards in a cascade of water. Costas slammed the locking points on either side of his helmet and the visor sprang open, flooding him with air.

Jack settled back in the water in the open hatch in the floor of the submersible, breathing in great gulps, his arms draped over Costas’ shoulders, his eyes dazzled by the fluorescent glow inside. He reached his left arm up to the camera pod on the front of his helmet, detached it and lowered it in front of his face, then pressed the record button. The little LCD screen lit up and showed a video image, at first a scatter of reflected light from particles in the water and then a sharp view of the chamber in the volcano. It was all there. It had been real. He saw the skulls, the basin, the paintings on the cave wall. The image zoomed in to his final discovery, the extraordinary pillars, and then it went blank. He carefully placed the camera pod on the floor of the submersible, then shut his eyes with relief and slumped back over Costas’ frame, breathing deeply, letting the energy return to his limbs.

‘Jack.’

‘What is it?’

‘The bear hug.’

Costas’ forearms were up on the edge of the floor, entirely supporting Jack’s weight, and his head was wedged sideways against Jack’s helmet. Jack gave a half-hearted kick, then slumped back. ‘Can’t,’ he gasped. They remained still for a moment, locked together, and then they both began to laugh uncontrollably. They kicked and heaved, and Jack pulled himself up until he was sitting on the edge of the hatch. He reached out to help as Costas clawed his way up on the other side and sat down heavily. They stared at each other’s dripping forms, and then reached across the water and slapped hands. Jack closed his eyes.

They had come here on a wing and a prayer.

But they had done it.

They had returned to Atlantis.