As they passed above the sixty-metre mark their regulators began to replace helium with nitrogen as the main inert gas. Soon their breathing mixture would differ from atmospheric air only in the enriched oxygen that was injected during the final few metres to scrub their bloodstreams of any excess nitrogen.
Costas led the way as the stairway began to constrict into a narrow tunnel. After a final step it veered right, apparently following a natural fissure, before regaining its original course and promptly depositing them at the entrance to another cavern.
“Here’s our intersection, bang on target.”
Their headlamps revealed a chamber about ten metres long by five metres wide, with doorways on all four sides. The decompression stop had briefly revitalized Jack and he swam forward for a closer look. In the centre was an oblong table flanked by pedestals set about two metres from each corner. The table was hewn from the rock and had a raised rim like the upturned lid of a sarcophagus. The pedestals were free-standing basins like the fonts of medieval churches.
“There are no runnels for blood and it would have been impossible to bring a large animal this far into the mountain,” he said. “Sacrifices tended to be public affairs and whatever went on here could only have been attended by a select few.”
“An ablution table, for ritual purification?” Costas suggested.
Katya finned over to the doorway opposite their point of entry. She peered into the corridor beyond and briefly switched off her headlamp.
“I can see light,” she said. “It’s barely discernible, but there are four separate pools evenly spaced.”
Jack and Costas swam over. They too could see faint smudges of hazy green.
“We’re only fifty metres below sea level and a few metres inside the cliff face.” Costas flicked his light back on as he spoke. “It’s early morning outside, so there should be some vestigial light at this depth.”
“The corridor corresponds with one of the parallel lines jutting out from the wing of the eagle,” Jack said. “I’ll bet they’re accommodation quarters, with windows and balconies overlooking the pyramids. Just like the Minoan complex on the cliffs of Thera, a magnificent location which served the monastic ideal yet also dominated the population on the coast below.”
“We could get out through one of those windows,” Katya suggested.
“Not a chance,” Costas said. “They look like ventilation shafts, probably less than a metre wide. And we don’t have time to explore. Our map’s held true so far and I vote we follow it.”
Just then a vibration coursed through them, a blurring of the water that made Jack suddenly fear he was about to black out. It was followed by further vibrations and then a series of dull hammering noises, each one preceding a muffled sound like breaking glass a long distance off. There was no way of telling the direction the sound was coming from.
“The submarine!” Katya exclaimed.
“It’s too distinct, too contained,” Costas said. “Any explosion in the Kazbek and we wouldn’t be here talking about it.”
“I’ve heard that sound before.” Jack was looking at Costas, his anger palpable even through the visor. “I think it’s the vibration of shells tearing through a hull. There’s a gun battle raging on the surface above us.”
“Whatever it is, we need to find a way out now,” Costas urged. “Come on.”
They finned towards the entrance that marked the right-hand turn indicated by the symbol. After passing the basins, Costas paused to check his compass bearing.
“Due south,” he announced. “All we do now is follow this route as far as it goes and then turn left.”
Katya was approaching the entranceway a few metres ahead of the other two. She suddenly halted.
“Look up,” she said excitedly.
Above the entranceway was a huge lintel carved out of the rock. The front was deeply scored with symbols, some occupying the full half-metre height of the slab. They were separated into two groups of four, each group surrounded by an incised boundary like a hieroglyphic cartouche.
There was no mistaking what they were.
“The sheaf of corn. The paddle. The half-moon. And those Mohican heads,” Katya said.
“It’s the final proof,” Jack murmured. “The Phaistos disc, the golden disc from the wreck. Both of them came from this place. We’re looking at the sacred script of Atlantis.”
“What does it mean?” Costas asked.
Katya was already consulting her palm computer. She and Dillen had programmed in a concordance which matched each of the Atlantis symbols with its syllabic equivalent in Linear A, providing a best-fit translation from the Minoan vocabulary so far deciphered.
“Ti-ka-ti-re, ka-ka-me-re.” Katya slowly enunciated the sounds, her Russian inflection giving a slight burr to the final syllables of each word.
She scrolled through alphabetically, Jack and Costas watching the flickering words as they appeared on the LCD display.
“They’re both in the Minoan lexicon,” she announced. “Ti-ka-ti means route or direction. Ka-ka-me means dead or death. The suffix re means to or of. So it translates as ‘the route of death,’ ‘the way of death.’ ”
They peered up at the inscription above their heads, the symbols standing out as crisp as if they had been carved only days before.
“That doesn’t sound too promising,” Costas said glumly.
Jack winced and the other two looked at him with renewed anxiety. He summoned up his remaining energy and powered ahead into the passageway.
“This should be the last leg. Follow me.”
Costas lingered for a moment to tie the final spool of tape to his backpack. All he could see of the other two was the turbulence in their wake; the passageway sloped up at a shallow angle. As he finned after them the reassuring glimmer of their headlamps appeared further up the tunnel.
“Keep your ascent rate below five seconds per metre,” he instructed. “Our time in that chamber counts as another decompression stop, and with this gradient we shouldn’t need to halt again before reaching the surface.”
The floor was rough as if deliberately left unfinished to provide a better grip. On either side were parallel grooves like the ruts in ancient cartways. Suddenly they were at the entrance to another chamber, the walls falling away into pitch darkness yet the ramp continuing upwards.
It was a cavernous space that dwarfed even the hall of the ancestors. All around them were undulating folds of rock that seemed to ripple as they panned their headlamps back and forth. The sides plummeted into a yawning chasm, the sheer drop broken only by gnarled contusions of lava that punctuated the walls like knots in old oak. Everywhere they looked were twisted rivers of lava, testament to the colossal forces that blasted through the chamber from the molten core of the earth.
“The core of the volcano must only be a couple of hundred metres south,” Costas said. “Magma and gas punched through the compacted ash of the cone to leave gaping holes and then solidify. The result is this giant honeycomb effect, an expanded hollow core intermeshed with a lattice of basalt formations.”
They peered through the crystal-clear water and the ramp revealed itself as a giant causeway, an immense spine of rock that spanned the space as far as they could see. To the left their headlamps played over another massive dyke, followed by another one an equal distance beyond, both projecting at right angles from the central spine and merging with the wall of the chamber.
It was Costas who pointed out the obvious, the reason why the geometry seemed so strangely familiar.
“The central spine is the upper wing on the symbol. The dykes are two of the projections to the left. We’re on the home stretch.”