David Gibbins - The Crusader's gold

“We’ll keep the power line attached to the DSRV as long as we can, as well as the fibre-optic cable,” Costas said. “Normally the DSRV pilot would be able to see everything we see on the screen, but before the DSRV moves off we’ll have to disengage the power line and run the probe from the internal battery.” He adjusted a large dial below the screen, then turned and peered at Jack through his mask, remembering the debilitating effect of the gunshot wound that had nearly ended his friend’s life on a very different dive, deep in the Black Sea six months before. “You okay?”

“This new E-suit heating system is working wonders,” Jack replied simply.

“Without the coil the water in the tunnel would actually be below zero,” Costas said cheerfully. “It’s fresh water, from the glacier, so it freezes more quickly than salt water. We’d be ice before you could say scotch on the rocks.”

“Thanks for the thought.” Jack looked down with some scepticism at the coil, a wavering tendril of microfilaments hanging below them. It would be paid out from the device as they went in, and keep the newly melted water from freezing up again and entombing them inside the berg.

“It should work,” Costas added. “In theory.”

“Let me guess. I won’t even say it.”

Costas’ eyes glinted at Jack as he reached up to his shoulder and pressed the external channel on his communications console. “Ben, we’re on our way. Estimated time of arrival at the ten-metre disengagement depth, twenty minutes. Out.”

Jack watched beneath his fins as their entry hole into the berg receded far below, a shimmering patch of blue obscured by the swirl of heated microfilaments that trailed behind them. Twisting down the centre was the battery cable and the umbilical bringing in their nitrox and sucking out their exhaust, their lifeline to the world outside. Jack raised his head and watched in fascination as the borer carved a perfectly smooth tunnel through the ice, proceeding upwards at a 45-degree angle at a rate of more than two metres per minute. He had no sense of the water temperature in his E-suit, but the changing thermostat readout on his environmental regulator reflected the blast of warm water that was being ejected from the borer and driving the machine into the ice. Ahead of them their lamps lit up the wall of the tunnel, a dazzling spectacle of white, yet Jack knew that without artificial light they would be entering a world of total blackness, hemmed in on all sides by an unimaginable thickness of ice which had blocked out the last vestiges of the sun’s rays far above them.

“Okay,” Costas said. “We’ve reached ten metres external water depth. I’m going to level out and disengage.”

Costas adjusted the heat output controls on the panel in front of him, easing off on the lower elements so the borer would melt more ice above and gradually become horizontal. Jack watched their progress on the LED screen, a 3-D isometric image of the berg identical to the one Lanowski had shown them earlier that day. The image had been generated by the surface team using ultra-high-frequency sonar, created from thousands of data points where the sound waves had met differential resistance from frozen cracks and fissures in the berg. Lanowski had plotted a best-fit point of entry and route to minimise the chance of following a frozen meltwater fissure and rupturing the berg, and so far his plot had held true. The ice they had passed through had all been the cloudy white ice of the glacier, as hard as rock, formed a hundred thousand years ago in the depths of the Ice Age.

Costas reopened the external channel on his intercom receiver. “Ben, this is Costas. Do you receive me, over?”

“Costas, this is DSRV, we receive you loud and clear, over.”

“We’ve reached the disengagement point, over.”

“Roger that. We’ve got you on screen as long as you’re hooked up. Be advised, we have a meteorology warning from the captain of Seaquest II. There’s some thermal disturbance on the edge of the ice cap, a cold air mass moving in from the east. It may be nothing significant, but the captain’s pulling back another mile from the fjord as a safety precaution. You have the option to abort. Over.”

Costas and Jack looked at each other through their visors. “We’re carrying on,” Costas replied. “We’re only fifty metres from our target, and we’re not going to hang around. We’ll be out of here within the hour. But you must leave now. Over.”

“Roger that. Send up the radio buoy when you’re clear of the berg and we’ll pick you up. Standing by to receive umbilical. Over.”

Costas flipped a switch on the control panel in front of him and pulled out the power cord from the ice-borer. For an alarming moment the device went dead, and Jack could almost see the water around him beginning to freeze up. Then the LED screen and forward light array reactivated as the battery came on line, and the water began to shimmer again.

The two men turned towards each other in the narrow confines of the ice tunnel, their visors only inches apart. Costas talked them through the procedure they had practised repeatedly before leaving the DSRV, each man visually checking the other as they worked methodically through the steps.

“Engage rebreather.”

Jack copied Costas and opened the outlet valve of the rebreather on his chest, then turned the knob under his helmet that activated the flow of gas into the silicon rubber skirt that sealed over his nose and mouth. The first lungful of oxygen sent a tingle down his arms and legs, an invigorating effect he relished every time they used rebreathers. He grasped the umbilical hose with his right hand and with his other hand closed the nitrox port on his helmet, his body wedged awkwardly on his elbows against the wall of the tunnel and pressed up against Costas.

“Disengage umbilical.”

Simultaneously the two men pulled the nitrox hoses from their helmets and dropped them to the floor of the tunnel, and Costas released the power cable he had been holding. As they sucked on their rebreathers they watched the coiled mass of the umbilical slither off behind them and disappear over the bend in the tunnel, dropping down their entry route towards the open sea. The microfilament tendrils keeping the tunnel liquid wavered and undulated as if they had been caught in a breeze, then gradually became more stable, spreading out over the entire width of the tunnel.

“Ben, we’re disengaged. We’ll be out of communication range once we hit that mass of meltwater ice. Looking forward to a hot brew when you return. Over.”

“Roger that. Good luck. Out.”

They were now completely cut off from the outside, dependent solely on each other and the array of equipment that festooned their bodies. As Jack watched the umbilical disappear he had felt a pang of unease, a warning sign of his secret vulnerability as a diver, the lurking claustrophobia he constantly fought to suppress. Years before he had nearly died in a submerged mine shaft, his life saved only by buddy-breathing with Costas, and the trauma had been reawakened in the labyrinth of Atlantis, when his wound had left him weakened and exposed. He knew Costas was aware of his battle, and the unspoken bond between the two men was a source of strength. Jack gripped the guide rail behind the probe and forced himself to concentrate on the excitement ahead.

“We’re dead on target,” Costas said. “Check out the screen.”

Directly in front of them the LED display showed an anomalous form, the image created by the sonar data points around the mass of meltwater in the heart of the berg that had mystified Cheney and the NASA team. Even the ultra-high-frequency sonar had failed to penetrate further, and from this angle there was no sense of the extraordinary shape which had been so clear from the vertical sonar images. In the centre of the dark mass was a red cross-hair where the ice-corer had picked up the timber sample, and slightly above it a green cross-hair which marked their objective.