He powered the transverse stern thruster and brought the ADSA round on a southerly course parallel to the rock face. Twenty metres below him the sediment maelstrom seemed to seethe and boil, a forbidding netherworld halfway between liquid and solid that lapped the wall of the canyon. By maintaining a constant altitude above the slope he was steadily climbing, the depth gauge registering a rise of almost a hundred metres in his first half- kilometre along the canyon wall.
As the gradient angled more sharply, a sector of the canyon floor appeared that was entirely denuded of sediment. Jack guessed it was an area where sediment had accumulated and then avalanched down the slope. He knew this was a danger zone; any disturbance could dislodge sediment further up the slope and engulf him.
The exposed sea floor was covered in a bizarre accretion, a crystalline mass stained a sickly yellow by the hydrogen sulphide that poisoned the water. He bled the buoyancy reservoir and sank down, at the same time extending a vacuum probe to sample the accretion. Moments later the results flashed up on the screen. It was sodium chloride, common salt. He was looking at fallout from the evaporation thousands of years before, at the vast bed of brine that had precipitated into the abyss when the Bosporus had sealed off the Black Sea during the Ice Age. The canyon Jack had christened the Atlantis Rift would have been a sump for the entire south-eastern sector of the sea.
As he jetted forward, the carpet of brine became patchy and gave way to a contorted landscape of shadowy shapes. It was a lava field, a jumble of frozen pirouettes where magma had welled up and solidified as it met the frigid water.
His view was interrupted by an opaque haze that shimmered like a diaphanous veil. The external temperature gauge soared to a horrifying 350 degrees Celsius, hot enough to melt lead. He barely registered the change before he was jolted violently forward and the ADSA spiralled out of control towards the canyon floor. On impulse he switched off the thrusters just as the ADSA bounced and then came to rest facedown, the forward battery pod immobilized between folds of lava and the visor pressed against a jagged eruption of rock.
Jack raised himself on all fours inside the ADSA and crouched low over the control panel. He saw with relief that the LCD screens were still functioning. Once again he had been incredibly lucky. If there had been significant damage he would probably have been dead by now, the external pressure of several tons per square inch bearing down on any weakness and guaranteeing a swift if hideous end.
He put a mental block on the nightmarish world outside and concentrated on extricating himself from the lava folds. The propulsion unit would be of little use as it was mounted on the back and only provided lateral and transverse thrust. He would have to use the buoyancy compensator. The manual override was operated from a two-way trigger on the joystick, backward pressure bleeding air in and forward pressure venting it.
After bracing himself, he squeezed hard. He could hear the burst of air entering the reservoir and watched the dial creep up to maximum capacity. To his dismay there was absolutely no movement. He emptied the reservoir and filled it again, with the same result. He knew he could not repeat the procedure without depleting the air supply beyond safety margins.
His only fallback was to wrest the ADSA physically from the seabed. So far he had only been deploying the ADSA in submersible mode but it was also a true inner-space suit, designed for the underwater equivalent of moon walking. Despite its cumbersome appearance, it was highly mobile, its thirty-kilogramme submerged weight allowing movement that would have been the envy of any astronaut.
He carefully extended his arms and legs until he was spread-eagled. After angling the pincers into the seabed and locking the joints, he wedged his elbows against the upper carapace with his hands splayed below. Everything now depended on his ability to rip the battery pod from the vice of rock that was holding it.
With every fibre in his being Jack heaved upwards. As he arched back into the harness he was convulsed by pain from his gunshot wound. He knew it was now or never, that his body had been pushed to the limit and would soon lose the strength to do his bidding.
He was about to collapse in exhaustion when there was a grinding sound and a barely perceptible upward movement. He threw in all his reserves and strained one last time. Suddenly the ADSA broke free and sprang up on its feet, the jolt throwing him against the console.
He was free.
After flooding the buoyancy reservoir to prevent the ADSA from rocketing upwards, he looked around him. Ahead were undulations where slow-flowing rivers of lava had solidified into bulbous pillows of rock. To his right was a huge lava pillar, a hollow cast five metres high where quick-flowing lava had trapped water which had then boiled and pushed the cooling rock upwards. Next to it was another eruption of igneous rock, this one more like a miniature volcano that showed up yellow and red-brown in the floodlight. Jack guessed that the scorching blast of heat that had jolted him had come from a hydrothermal vent, an open pore in the seabed where superheated water belched up from the magma lake below the rift. As he looked at the miniature volcano, the cone ejected a jet-black plume like a factory chimney. It was what geologists called a black smoker, a cloud laden with minerals that precipitated to blanket the surrounding sea floor. He thought back to the extraordinary entrance chamber to Atlantis, its walls shimmering with minerals which could well have originated in a deep-sea vent thrust upwards as the volcano formed.
Hydrothermal vents should be teeming with life, Jack thought uneasily, each one a miniature oasis that attracted larval organisms drifting down from far above. They were unique ecosystems based on chemicals rather than photosynthesis, on the ability of microbes to metabolize the hydrogen sulphide from the vents and provide the first links in a food chain utterly divorced from the life-giving properties of the sun. But instead of armies of blood- red worms and carpets of organisms, there was nothing; the lava chimneys loomed around him like the blackened stumps of trees after a forest fire. In the poisonous depths of the Black Sea not even the simplest bacteria could survive. It was a wasteland where the wonder of creation seemed to have been eclipsed by the powers of darkness. Jack suddenly wanted to be away from this place that was so utterly devoid of life, that seemed to repudiate all the forces that had brought him into existence.
He tore his gaze away from the bleak scene outside and scanned the instrument display. The sonar showed he was 30 metres from the western face of the chasm and 150 metres shallower than the wreck of
He looked ahead and saw a milky haze like a towering sand dune. It was the leading edge of a drift of unstable sediment, an indication that the area of substrate exposed by the avalanche was coming to an end. All round him were scour marks caused by previous slides. He needed to be above the zone of turbulence in case his motion triggered another avalanche. He closed his left hand round the buoyancy control and his right hand on the thruster stick, at the same time leaning forward for a final look outside.
What he saw was a terrifying apparition. The wall of silt was slowly, remorselessly swirling towards him like some vast tsunami, all the more horrifying because there was no noise. He barely had time to press the buoyancy trigger before he was engulfed in a whirling storm of darkness.
CHAPTER 27
Costas blinked furiously as the scalding water dripped off his face. He had been sent sprawling on the rock floor after being thrust for an appalling moment into the vapour column, the vast pillar of white that rose in front of him to the oculus far above.
He was back in the audience chamber, back where he had last seen Jack. He had passed out so many times over the last few hours that he had lost all measure of time, but he guessed that a night had gone and it was now a full day since they had stumbled out of the labyrinth into the glare of Aslan’s searchlight.
He steeled his mind for what would come next.
With his face pressed against the floor he could just make out a veiled and blindfolded figure seated on the throne a few metres from him. As it came into focus the blindfold was ripped off and he realized it was Katya. She looked at him without recognition, and then her eyes widened in horror at his appearance. He gave her his best
