Atlantis

safety measure for the rescue crew. With our own hatch shut we can couple with the hull, open the casing hatch, pump the outer chamber dry and open the escape hatch two metres below with a robotic arm. We then use the DSRV’s external sensor array to test the interior environment without actually exposing ourselves to it.”

Costas nodded at the crewmen and they set about securing the seal. After manually locking the ring they crawled to the aft part of the submersible and sat side by side at a small console. With the flick of a switch the covering over the hatch in front of Katya retracted into the DSRV’s hull casing, revealing a concave Plexiglas dome which lit up as a floodlight activated and the crewmen set about decoupling the submarine’s hatch. A few moments later there was a sharp hiss as the seawater inside the chamber was pumped out and replaced with air from one of the DSRV’s external high-pressure cylinders.

“Chamber evacuated and equalized,” one of the crewmen said. “Activating robotic arm now.”

Katya squeezed in between Costas and Jack for a better view. Below them they could see a thin tube terminating in a grapple-like device, its movement controlled by one of the crewmen using a small joystick and navigation screen.

“It works by pressure differential,” Costas explained. “We’ve filled the chamber with air at ambient barometric pressure, the same as inside the DSRV. We hook that arm to the hatch, ratchet it up to exert some pull, then slowly decrease the pressure in the chamber until it’s lower than the submarine. Then bingo, it springs open.”

They watched as the robotic arm disengaged the safety lock and clenched the central handle, the shaft straightening as tension was applied. The crewman at the far end of the console was concentrating on a screen which gave him a close-up view of the casing.

“Pressure one bar. Reducing now.” He cracked open a valve on a pipe above him and activated an extractor pump which drew air out of the chamber.

“Point nine five bar. Point nine zero. Point eight five. Point eight zero. Now!”

As he snapped the valve shut they could see the hatch waft up as if it were riding a wave. The arm automatically retracted and pulled the hatch taut against the side of the chamber. They could see through into the bowels of the submarine, the floodlight dancing off piping and bulkheads in the passageway below.

“Pressure point seven nine five bar.”

“About what I expected.” Costas looked at the crewmen. “Give me full environmental specs before we compensate.”

A sensor array incorporating a gas spectrometer, a Geiger counter and a radiation dosimeter was lowered into view from the external pod.

“Radiation dose zero point six millirems per hour, less than you get in an airliner. General toxicity level moderate, with no indication of significant gas or chemical leakage. High ammonia content probably due to organic decay. Oxygen eight point two per cent, nitrogen seventy per cent, carbon dioxide twenty-two per cent, carbon monoxide zero point eight per cent, a little risky for prolonged exposure. Temperature plus two degrees Celsius.”

“Thanks, Andy.” Costas looked wryly at Jack. “Stepping in there now would be like landing on top of Everest in tropical kit with a mouthful of rotten eggs.”

“Wonderful,” Jack said. “Why is it this kind of thing always happens when you take the lead?”

Costas grinned and looked back at the console. “Andy, compensate to ambient using pure oxygen and engage CO₂ scrubbers.”

There was a sharp hiss as the DSRV began to bleed oxygen into the hatch from its external gas cylinders.

“The Akula class has its own scrubbers,” Katya said. “If we could activate them they’d do the job for us. There’s also a unit that breaks down seawater to release oxygen. These subs can stay down for months at a time with air that’s cleaner and better oxygenated than on the surface.”

Costas wiped the sweat from his brow and looked at her. “It would take too long. The battery which powered those systems would have depleted within a few months of the auxiliary diesel shutting down, and I’d prefer to save the DSRV battery for reactivating the emergency lighting. Our own scrubber incorporates carbon monoxide and hydrogen burners as well as a range of chemical filters.”

A voice broke in from the console. “We’ve reached ambient pressure. In ten minutes the scrubbing cycle will be complete.”

“Right,” said Costas. “Time to kit up.”

They wore close-fitting E-suits, all-environment shells of Kevlar-reinforced crushed neoprene which were an amalgam of the latest diving drysuits with US Navy SEALs chemical and biological warfare gear. Wrapped round their calves were flexible silicon fins which could be pulled down over their feet underwater.

Costas quickly briefed them as he clipped on his straps. “We should be able to breathe safely but I suggest we wear full-face masks anyway, as the regulators will moisturize and warm up the air as well as filter out residual impurities. There’s a supplemental oxygen feed which kicks in as soon as the sensor detects atmospheric depletion.”

The mask was a silicon-enriched helmet which conformed closely to the shape of the face. After finalizing his own gear, Jack helped Katya don her self-contained life support system, a streamlined polypropylene backpack which contained a compact oxygen rebreather, a multi-stage regulator and a triple set of titanium-reinforced cylinders pumped up to eight hundred times barometric pressure. The IMU cylinders were ultralight and slimline, weighing less than a single old-fashioned scuba set and ergonomically designed so they were hardly aware of the extra bulk.

On their wrists micro-consoles displayed full environmental data as well as computations for a range of breathing mixtures from the helium, oxygen and nitrogen in the cylinders. The gas was mixed automatically, the computer taking account of depth, dive profile, temperature and even individual physiology.

“The intercom should allow us to communicate with the DSRV,” Costas said. “Switch it on when you activate the SCLS system just before we go in.”

After they had double-checked each other, Jack took down a 9-millimetre Beretta 92FS from a shelf above the hatch. He slammed a fifteen-round magazine into the butt and sealed the pistol in a waterproof holster with a spare magazine on his chest.

“Standard equipment.” He glanced reassuringly at Katya, remembering their conversation the night before about the risks involved. “You can never be too safe in this game.”

“Dr. Howard. Urgent message from Seaquest.”

“Put it on audio.” Jack snapped open his visor and took the mike from the crewman. “This is Howard. Over.”

“Jack, this is Tom.” The voice was crackling with static. “That weather front has finally hit us. Violent electrical storms, visibility down to fifty metres. Storm force ten and rising. Far worse than I feared. I cannot hold present position so close to the island. I repeat, I cannot hold present position. Over.”

The urgency in his voice was absolutely clear despite the disturbance.

Jack clicked the reply button. “What’s the forecast? Over.”

“One of the biggest fronts ever recorded at this time of year. Your chance to abort is now. Over.”

The DSRV was too large to be deployed through Seaquest’s inner berth and instead had been swung out over the stern davits. The experience had given them a sharp appreciation of the perils of returning in rough seas.

“What’s the alternative? Over.”

“You’d be on your own for twenty-four hours. I intend to take Seaquest north twenty nautical miles behind the front and then follow it back south. Over.”

“There’s no way the DSRV could follow Seaquest that far underwater,” Costas muttered. “The battery’s designed for life support during rescue operations and would only power us a couple of miles before draining.”

Jack paused before raising the mike. “Tom, give us a moment. Over.”

In the brief silence Jack looked at the others and received a nod from each of them. Andy and Ben were IMU veterans, Andy a submersibles specialist who was Costas’ chief technician and Ben a former Royal Marine who had served in the Special Boat Section before joining Peter Howe’s security department. Both men would follow Jack anywhere and were deeply committed to the goals of IMU.