Katya was inspecting the steps leading down to the platform.
“This must be where they brought the bodies before placing them on the slab for their final journey,” she surmised. “The ruts on the ramp are two metres apart, just right for a bier. They must have been worn down by the feet of pallbearers over countless thousands of funerary processions.”
Jack was staring into the depths of the chasm, all his imagination marshalled to conjure up an image of the ritual last performed at this spot millennia before. He had excavated many ancient burial sites, the dead often telling a better story than the detritus of the living, and he had expected their greatest discovery to be a rich necropolis. Now he knew the only mortal remains of the people of Atlantis were encoded within themselves, in the genes of those intrepid seafarers who had escaped the flood and spread the seeds of civilization.
“So this is the underworld of the ancients,” he said, his breath short. “And the Styx was no placid backwater but a burning river of fire.”
“Old Charon the boatman would have taken a raincheck on this one,” Costas said. “It looks like the gates of hell to me. Let’s get out of here before we wake up the god of this place and he reactivates the furnace.”
As they finned up the final section of the ramp, Jack was gasping. His ragged breathing was audible and Katya turned towards him in alarm. Costas had stayed close by and now pulled his friend to a halt.
“Time to buddy-breathe,” he said.
After fumbling briefly behind his backpack he produced a vulcanized hose which he pushed into an outlet on Jack’s manifold. He opened the valve a few turns and there was a hiss as the two systems equalized.
“Thanks.” Jack’s breathing was suddenly easier.
“We’ve got a problem,” Costas announced.
Jack had been concentrating on his breathing but now looked up at the rock face looming in front of them.
“A lava plug,” he said bleakly.
About five metres ahead the ledge terminated at the north-eastern extremity of the chamber. They could just make out an entrance, as wide as the walkway and capped by a lintel. But these features were obscured by a giant clot of solidified lava, an ugly eruption that had oozed into the chasm and left only a small aperture near the top.
Costas turned to Jack. “We’re only eight metres below sea level, within the ten-metre safety margin for oxygen toxicity, so while we’re working this one out we may as well cleanse our systems.”
He switched his and Katya’s computers to manual override and cranked open the oxygen valves on their manifolds. Then he and Jack swam in tandem to the hole and peered into the space beyond.
“The lava tube must have broken through the basalt into the passageway some time after the flood,” Costas said. “The aperture is the result of a gas blowout. If we’re lucky there’ll be a cavity all the way through.”
Jack pulled himself into the jagged slit so his head and shoulders disappeared. Beyond the constriction he could see the cavity opening out like a ventilation duct, the walls mottled with igneous contusions where the gas had exploded through the cooling lava with the force of a jet afterburner.
“There’s no way we’ll get through with our equipment on,” he said. “After the blowout the lava must have expanded as it solidified, narrowing the first few metres to a tunnel barely wide enough for Katya, let alone me or you.”
They knew what they had to do. Jack began to unbuckle his cylinder harness.
“It makes sense for me to go first. You and Katya both still have your reserve. And I’m the one who can free-dive to forty metres.”
“Not with a bullet hole in your side.”
“Let me blast some oxygen into the tunnel,” Jack replied. “I can see undulations in the ceiling that might trap pockets of gas and provide a safety stop.”
Costas paused, instinctively reluctant to expel any of their dwindling supply, but he saw the sense in Jack’s words. He detached a regulator second stage from his backpack and passed it over. With his long reach Jack extended the hose as far as he could into the fissure and pressed the purge valve. There was a thunderous roar as the oxygen erupted into the space and cascaded like white water along the upper surface of the rock.
Costas watched intently as the readout on his contents gauge dropped below fifty bar and the reserve warning began to flash.
“Enough!” he said.
Jack released the purge and placed the regulator just inside the lip of the aperture. As he eased off his backpack and wedged it in a fold in the lava, Costas detached the tape from his back and tied it to Jack’s upper arm.
“Standard rope signals,” he instructed. “One pull means OK. Two pulls means you want another blast of oxygen. Continuous pulls means you’re through and it’s safe for us to follow.”
Jack nodded as he checked to make sure the reel was clear. He would be cut off from the intercom as he would need to retract his visor to access air pockets in the tunnel. He released the safety lock on his helmet and looked across at Costas, who had just confirmed on his computer that they had satisfied decompression requirements.
“Ready.”
“Transfer to regulator.”
As Costas disengaged the umbilical, Jack shut his eyes tight and flipped back his helmet, at the same time shoving the regulator second stage in his mouth and extracting the face mask kept in a side pocket for emergency use. He pressed it to his face and blew through his nose to clear the water, remaining still for a few moments to let his breathing rate subside as the shock of the cold wore off.
After unclipping a hand-held torch, Jack drew himself up to the aperture, Costas following close behind to ensure the hose was not stretched taut. As Jack grasped the lintel he felt an indentation where the lava had folded over the rock surface. His fingers traced the form of a symbol cut deep into the basalt.
He turned towards Katya and gesticulated excitedly. She gave an exaggerated nod before returning her gaze to him, clearly more concerned by his chances of making it through the tunnel.
Jack turned back and relaxed completely, his body suspended from the lintel and his eyes closed. Using the technique of a free diver he breathed slowly and deeply to saturate his body with oxygen. After about a minute he gave the OK signal to Costas and placed his hand over the regulator. He took five quick breaths, then spat it out and launched himself forward in a frenzy of bubbles.
Costas reached out to grasp the tape which was their precious lifeline. As it began to slip through his fingers he spoke quietly under his breath.
“Good luck, my friend. We need it.”
CHAPTER 22
For the first few metres Jack had to claw his way through the narrow confines of the tunnel where the lava had sagged over the entrance. He could feel his suit rip as he squeezed past the razor-sharp knots of lava. He glanced back to make sure the tape was undamaged and then set off rapidly down the tunnel, his arms extended forward and the torch shining directly ahead.
As he rocketed along he could sense the gradual incline where the lava flow conformed to the rising angle of the passageway. He flipped over and saw pools of luminosity on the ceiling where the oxygen from Costas’ regulator had collected. Almost exactly a minute after taking his last breath he popped his head into a pool that filled a fissure in the lava. He took three breaths in rapid succession, at the same time checking his depth gauge and breaking out a Cyalume chemical lightstick to leave floating in the bubble as a beacon for the others to follow.
“Three metres below sea level,” he said to himself. “A piece of cake.”
He ducked down and pushed off again into the passageway. Almost immediately it forked. He guessed that one passage would lead to safety and the other would follow the vent where the lava had blown through from the core. It was a life or death decision which would determine the fate of the other two.
After checking his compass Jack swam resolutely up the left-hand passage, exhaling slightly to prevent his lungs from rupturing as the pressure decreased. A shimmering lens of iridescence appeared before him, a surface
