James Barrington - Foxbat

‘Good. Keep them out there.’

‘GWO, Flyco, the Merlin’s on deck and secured.’

‘Good. All positions, GWO. Release Goalkeeper to unrestricted operation. Engage full ECM. Advise the ships in company.’

Goalkeeper is a fully autonomous close-in weapon system manufactured by Thales Nederland, specifically designed to intercept incoming shells, and both ballistic and sea-skimming missiles. Its heart is a 30mm seven-barrel Gatling gun – the same weapon that’s used as a ‘tank-buster’ on the American A-10 Thunderbolt II – firing four thousand two hundred rounds a minute, guided by an X-band search radar and a combined X-band and Ka-band monopulse Cassegrain engagement radar, backed up by an optical system.

Against a high-speed target like the Russian SS-N-22 Sunburn Mach 2 sea-skimming missile, it’s designed to detect it at 1,500 metres and complete the kill at 300 metres, in just over five seconds. By any standards, it’s a formidable weapon, and the Illustrious , like her sister ship Invincible , was equipped with three of them – one on the bow, the second amidships on the starboard side, and the third on the port side aft, just below the Flight Deck on a custom-designed platform.

In less than three minutes, Illustrious was fully secured, the gas-tight citadel in place, and positive air pressure established – a basic but very effective defence against chemical or biological attack – and the captain had just okayed the Military Flash signal that would be sent by satellite to advise CINCFLEET of the missile launch.

HMS Victorious , 200 miles west of Novaya Zemlya, Barents Sea

The Barents Sea is not the deepest water in the world by a long way. Much of the sea floor, especially to the west and south-west of Novaya Zemlya and to the north-east of Murmanskiy Bereg, is under six hundred feet deep. The captains of ballistic missile-carrying nuclear submarines prefer to lurk in areas where they have more freedom to manoeuvre than such shallows allow, but the latest orders hadn’t allowed Commander Richard Clare such latitude.

His redefined patrol area committed him to maintaining position about three hundred nautical miles to the north of the tip of Poluostrov Kanin, right on the edge of the deeper water of the central Barents Sea.

Clare hadn’t left the control room of Victorious in almost fifteen hours, apart from visits to the Officers’ Heads and a couple of trips to the Wardroom for sandwiches and coffee. No hot food had been prepared, or would be available, in the boat until it was secured from silent running, because cooking inevitably causes rattles and clangs as pots and pans are used. All off-watch crew members were confined to their bunk spaces, and all video and audio equipment had been switched off, apart from personal players using earphones only. The atmosphere in the boat was tense with anticipation, but very quiet.

Richard Clare was worried about on-board noise. He was also worried about seabed passive sonar arrays, ASW helicopters and hunter-killer submarines, like the small but silent and deadly Alphas.

But what worried him most was steaming around in the Russians’ back garden. The problem was, he couldn’t see any alternative to this.

The operational range of each Trident II D-5 SLBM carried by the Victorious was around five thousand miles. This meant that, from the boat’s current location, each of the eight MIRVs contained within the Trident’s warhead could easily strike a target anywhere inside the Confederation of Independent States – the territories of the old Soviet Union.

They could also, if the missiles’ navigation computers were reprogrammed, strike any target in the United States located to the east of a line drawn from Miami straight up to Minneapolis. Or, looking south and east rather than west, any target in China, Japan, the countries of the western Pacific Rim or Africa. In fact, about the only nations Victo rious ’s missiles couldn’t hit were Australia, New Zealand and South America.

He would have much preferred to be patrolling the wide, safe and, above all, deep waters of the North Atlantic, but in order to hit the targets he’d been given in North Korea, he had no option but to stay in the Barents Sea. The signal from CINCFLEET had made it perfectly clear that time was of the essence: to reposition the boat in the North Atlantic would have taken too long and, for most of the transit, North Korea would have been beyond the range of the Tridents, and that was unacceptable.

It made good tactical sense, but that didn’t mean Clare had to like it.

North American Aerospace Defense Command, Cheyenne Mountain, Colorado

For the last thirty years of the twentieth century, and well into the twenty-first, America’s anti-missile defences have relied upon DSP (Defense Support Program) surveillance satellites located in geosynchronous orbit some twenty-two thousand two hundred and fifty miles above the surface of the Earth.

The replacement system – SBIRS (Space Based Infrared System) – met substantial delays, but the new SBIRS Mission Control Station at Buckley Air Force Base in Aurora, Colorado, was commissioned more or less on time at the end of 2001, and now controlled the orbiting DSP satellites as well as operating the ALERT tactical warning centre.

The three front-line DSP birds were located over Central America, above the Indian Ocean and more or less over the middle of the Pacific Ocean. Two other spacecraft were available as orbiting spares, ready to take over when one of the satellites reached the end of its useful life.

Their sole purpose was to detect missile launches anywhere in the vast area under surveillance, using a huge infrared telescope designed to identify the heat flare of the missile’s rocket engine almost immediately after launch. The only thing that could delay detection was adverse weather, because thick cloud would prevent the infrared radiation reaching the telescope until the missile had cleared the cloud tops.

Over the Korean Peninsula, the weather was clear, and the Pacific Ocean DSP bird located the launch six seconds after the first-stage motor of the Taep’o-dong fired. Eleven seconds after that, the on-board computers had identified Ok’pyong as the launch site and calculated the missile’s initial trajectory.

Immediately, the DSP satellite transmitted the data to Buckley, where high-speed computers assessed the calculated trajectory to determine if the missile was on a ‘threat fan’: meaning if the flight-path could conceivably end in the United States or any allied nation. The initial data showed that the North Korean missile was heading east-south-east, which meant it couldn’t hit mainland America – but the Hawaiian Islands or even Mexico remained possible, though unlikely, targets.

Simultaneously, Buckley’s data links flashed details of the launch to NORAD. Moments later, a klaxon sounded, a light flashed, and a computerized voice announced ‘Missile alert! Missile alert!’ One of the huge vision screens displayed the warning ‘MISSILE EVENT’ in red in the top left-hand corner. In the top centre was the word ‘SECRET’ and below that, occupying most of the screen, was an outline map of the Pacific Rim, with the Korean Peninsula on the left-hand side.

Dominating this display was a large red dot positioned over Ok’pyong, indicating the launch point, and a line pointing east-south-east, showing the missile’s initial trajectory. At the end of the line was a quadrilateral shape, narrow where it joined the line but widening out from that point. This showed the threat fan: the computer system’s assessment of the area within which the missile could land, which was updated every second or two as additional data was processed.