While the Special Boat Squadron was on alert as well, however, it had happened that the 23rd Regiment was already set to go with full kit . . . and the Old Man, Colonel Wentworth, had seemed particularly eager to push this one through. Croft wondered if it had anything to do with that tin full of Yanks aft. . . .

The Horizon was properly classified as an anchor-handling tug and had originally been designed to haul oil-drilling platforms from one North Sea site to another. She was 250 feet long, with a high prow, with all of her superstructure crowded as far forward as it would go, and with a long, low afterdeck that gave her a decidedly unbalanced look. For the past twelve years she’d served as one of the supply boats that kept the North Sea oil platforms linked with the shore. On her voyages out from her home port in Middlebrough, she carried food, drilling mud, bits, shafts, piping, and all of the other myriad supplies and spare parts necessary to keep a small community of oil-field workers going. On her voyages back, she carried garbage.

This time, however, Horizon was carrying a piece of equipment unlike any she’d ever hauled before.

Forward, just aft of Horizon’s white-painted superstructure, a massive winch as thick as a man was tall rested on its supports, a six-inch steel cable paying out astern and vanishing into the churning white foam of the tug’s wake. A second cable, no thicker than Croft’s little finger, paralleled the first. It was attached to a com unit near the winch, where half-a-dozen SAS men were huddled together, keeping down and out of sight. The twin towers of Bouddica had slowly risen above the horizon over an hour ago, and it had to be assumed that men with binoculars were there, observing all that they could of the approaching supply boat. In Croft’s case, it didn’t matter; he was wearing civilian clothes—jeans, a heavy leather jacket over a wool sweater, and a balaclava—but most of the SAS men aboard were in their combat blacks.

Ready to go.

Briskly, Croft walked toward the crouching men. Sergeant Major Dunn acknowledged him with a nod but did not stand. He was listening to a headset pressed against his ear.

“How are they?” Croft asked.

“All’s right so far,” Dunn replied. The Horizon gave a heavy lurch as she slid into another trough, and Dunn grinned. “I’d say they’re getting an easier ride than we are.”

Croft nodded, then walked around to the side of the superstructure, peering forward. He could have gone up to the bridge for a precise figure, but he estimated—a guess close enough for government work, he decided—that the Bouddica complex was about five miles off.

“Pass the word to Tagalong,” he told Dunn. “Release in another minute.”

“Yes, sir.” Dunn held the headset’s mike close to his mouth. “Tagalong, Tagalong, this is Big Brother. Do you copy?”

It was time.

Crammed into the cockpit of the bus, he scarcely had room to breathe, much less stretch or move to unkink muscles too long cramped into a space smaller than any coffin. Worse, visibility was zip. Even though it was broad daylight above the surface, the light filtering down through the silt-filled water at a depth of forty feet was just enough to turn the world around him to a soft, gray murk. Before joining the Navy, Johnson had dived in plenty of different conditions, including at night, but he’d never gone diving in really deep water. Always before there’d been a bottom to give some sense of scale, perspective, and movement, even if only glimpsed in the moving beam of a hand-held diver’s light.

SDV evolutions, however, rarely had the luxury of light save for the faint green luminescence coming off the console instrumentation, and there was nothing beneath him now but the blackness of a night unchanging across a span of time measured in tens of millions of years. The bottom along this part of the central North Sea averaged forty fathoms—240 feet. The sensation was less like being aboard a small submarine than like what Johnson imagined it would be flying through the depths of space.

Certainly, this wasn’t what he’d dreamed about before joining the Navy, exploring the ocean depths and the wonders of the sea. There was almost nothing whatsoever to see here; his vision through the sub’s tiny forward window was sharply limited. His breathing sounded harsh in his ears. The submarine’s cockpit, like its passenger compartment aft, was flooded. Johnson was wearing a full-face mask, one equipped with a radio. His backpack rebreather had been switched off, and his mask hooked to the SDV’s life support.

“Tagalong, Tagalong” sounded in his earphones. “This is Big Brother. Do you copy?”

Peering ahead and up, he could just make out the vast shadow of the Horizon—Big Brother—churning through the water forty yards ahead. The sound of her screws was a pounding, hollow thunder.

“Big Brother, this is Tagalong,” Johnson said. His own voice sounded strangely muffled inside his mask. “I copy.”

Normally, the SEALs would have avoided communications this close to a target . . . but the link this time was by cable, not radio.

“Okay, Tagalong,” the voice said. “We’re five miles out now. We can see the complex fine. Any closer, and they might spot the tow. The boss says it’s time for your guys to let go.”

“Roger that,” Johnson said. “Any word on what the reception’s going to be like?”

“They’ve given us permission to come to one hundred meters” was the reply. “Don’t imagine they’ll sink us right off, not if they want to negotiate for their friends back on shore. But they don’t sound friendly.”

“Copy that. I’ll pass it on.”

“Right. Here’s the skinny. Your target is at a bearing of three-five-five true, range five miles. Any questions?”

Johnson took a last look at his instrumentation—not that he had that much to look at. The Mark VIII SDV didn’t pack that much in the way of fancy electronics. “Ready when you are, folks,” Johnson said. “Let ’er rip!”

“Hold on t’your hats, then, mates. Cast off!”

For the past four and a half hours, ever since leaving Middlebrough, Johnson had been riding the SDV’s diving and control planes to keep the vessel at a depth of between thirty and forty feet, but nothing else had been required of him in the way of steering. The Horizon had four times the SDV’s maximum speed and far, far more endurance.

It was for that reason that Murdock had suggested the idea of having an anchor tug tow the SEAL recon team most of the way to the objective.

Johnson hit the shackle release. There was a rattling clank from somewhere above his head, then a sudden lurch and a loss of forward velocity as Horizon’s cable slid free. His communications headset went dead too as the simple jack popped free of its receptacle on the SDV’s hull. The control yoke assumed a life of of its own as the vessel’s nose tried to come up, and Johnson forced it down.

The SEALs were all alone now.

Reaching to the channel select, he switched on the SDV’s intercom system. “Yo,” he called. “How’s the ride back there?”

“I’ve seen coffins with roomier amenities” came back the reply. A few feet behind Johnson’s back, in a separate compartment, four SEALs were crammed into a space only slightly larger than a typical phone booth. “I just hope those other guys can drive.”

Johnson chuckled. “Roger that. They said the target was in sight. Range five miles.”

“Yeah,” Roselli’s voice added. “Assuming, of course, they found the right rig. Don’t know about them, but all those derricks look the same to me!”

Johnson leaned forward, peering upward through murky water. The wake was thinning overhead in a churning wash of gray light. The Horizon was pulling away. Gently, gently, he eased the SDV’s yoke forward, taking the vessel deeper.

By craning forward and looking up, he could see the surface, a vast, shifting ceiling of liquid silver stretched overhead, with occasional shafts of pale light slanting through the water, illuminating myriad specks of drifting gunk. Below, the light faded rapidly into pitch blackness. The thunder of the Horizon’s screws were fading into the distance, and in another few moments, near-silence descended on the tiny undersea craft. The only sounds were Johnson’s breathing and the high-pitched whine of the Mark VIII’s electric motor. Like a World War II glider cast off from its tow plane, the bus was now on its own.

The bus was a Swimmer Delivery Vehicle, an SDV in military-speak. Standard equipment for the Navy SEAL teams, it was nonetheless an awkward compromise between politics and practicality—a compromise that more often than not was practicality ignored for political considerations.

The submarine navy had lobbied long and hard—and with complete success—to keep the Navy SEALs from appropriating money for submarines of any kind. Yet the SEAL Teams needed a vehicle that could travel underwater and undetected to its target, carrying the commandos and all their gear. They needed a vehicle that could travel hundreds of miles, so that the process of getting the thing launched wasn’t under observation by the enemy, and they needed one small enough that it could be transported by air anywhere in the world at virtually a moment’s notice. SEALs were trained to insert into an enemy area in many ways—by HAHO and HALO parachute drops, by helicopter, by the ubiquitous SEAL IBS. But SDV insertions theoretically gave the SEALs a covert insertion shared by none of the other services, one that they should have been able to use to supreme advantage.

And would have, had it not been for the infighting over the proper definition of a submarine, and over who got to use them.

As a result of the infighting, the SEALs were not allowed to acquire any dry submarines at all, meaning enclosed boats sealed against the sea that would allow their passengers to travel in relative safety and comfort for the hundreds of miles usually necessary in this sort of a deployment.

SEALs had to ride in boats that, while enclosed for streamlining purposes, were filled with seawater, their passengers and drivers breathing off life-support tanks stowed behind the bulkheads. Every minute in the water—especially in cold water—sapped a man’s strength and endurance, even when he was wearing a supposedly cold-proof dry suit, which meant that the time spent traveling to the objective had to be counted against his overall dive endurance time.

It was, Johnson reflected, a perfect example of the ancient adage learned by every recruit in boot camp: There were just three ways of doing anything in the Navy—the right way, the wrong way, and the Navy way.

As Johnson steered the SDV left, angling out of the Horizon’s wake, the little vessel lurched hard, rolling momentarily to starboard.

“Good afternoon, ladies and gentlemen,” Johnson said into his face mask mike, “and thank you for flying with SDV airways. We will be traveling today at an altitude of minus forty feet, so please make sure your cigarettes are extinguished, your seat belts are fastened, and your seat backs are in their full upright position. . . .”

“Just watch those barrel rolls over the runway,” Murdock’s voice came back. “Listen, Skeeter. How’s it look up at your end? You think you can find the thing without going active?”

“Hey, just sit back and relax,” Johnson quipped, shifting metaphors by mimicking an old bus commercial, “and leave the driving to us.”

His heart was hammering, his hands inside the gloves covering them were sweating. He’d never been this keyed up in his life, and he wasn’t sure whether the emotion was from excitement or stark terror.

Navigation—naviguessing, as Murdock had called it before they’d embarked—was an almost mystical blend of sixthsense awareness and pure luck. Since it was assumed that terrorists sophisticated enough to own an atomic bomb would also be sophisticated enough to rig some sort of simple hydrophone arrangement so that they could listen for the ping of an approaching sonar, the SEALs would be restricted to passive sonar for their approach.

Active sonar, using bursts of sound, “pinging,” like underwater radar to pinpoint objects such as ships or oil-rig platforms, was far better for undersea navigation, but it carried the risk of being detected by the target and alerting the enemy that a submarine was in the area. Passive sonar was strictly listening and therefore safely covert; hydrophones aboard the SDV could pick up the sounds other vessels in the water made. The problem was there was a lot of traffic in the North Sea, and the surrounding water was filled with eerie clanks, thumps, whirrs, and the churning throb of engines and screws.

In particular, the nearby screw sounds made by the Horizon just ahead drowned out nearly every other sound in the area, and Johnson had to listen hard over his headset to try to pick out the more distant noises. A small screen on the console in front of Johnson’s face gave a graphic representation of those sounds, what submariners referred to as the “waterfall” because of its appearance, like falling sheets of colored water. Most of the display was the jagged pulse of the Horizon’s powerful twin screws . . . but there was another element beyond the screw noise, a rhythmic clanking, that probably was coming either from the Bouddica complex or from the tanker moored nearby.

The current flowed southwest to northeast, coming up out of the English Channel at about three knots, and Johnson welcomed the added boost it gave him from astern, just like a tail wind for an aircraft.

At five knots, however, even adding in the assist from the following current, it would take the SEAL SDV well over half an hour to traverse five miles—longer when you added in the extra time required for maneuvering.

It gave Johnson a lot of time to think about what could go wrong.

All things considered, he thought, it was miraculous how fast things had come together when the plan depended on the cooperation of the men on the front lines instead of the REMFs who normally made the decisions. The way Johnson had heard it, the British SAS colonel had cleared the whole thing with his superiors, right down to arranging for the tow from the oil-field supply tug. The plan called for him to take the SDV up close to the pilings supporting Bouddica Bravo and park it there. While Horizon—with a hidden contingent of SAS commandos—moved in close and opened negotiations with the terrorists, the SEALs would climb the pilings, taking advantage of the distraction offered by the Horizon to make their move without being seen. Normally, such an operation would have been carried out under the cover of darkness, but Murdock had made the decision to go in during the daytime for two important reasons.

First and foremost was the time . . . or the lack of it. According to their intelligence briefing, the bad guys had set a deadline of 1200 hours Saturday for the last of their demands to be met. The sooner the SEALs could get aboard and find a convenient perch for an OP, the better. Horizon’s presence was important too, if for no other reason than that the tug was needed to tow the SDV close enough to the objective to make this operation possible. Having the tug approach at night, however, would definitely make the opposition twitchy, and more alert to the possibility of approaching combat swimmers.

And finally there was the simple and quite practical matter of finding the place. Right now, at a depth of forty feet, there was just barely enough light to see out to a range of perhaps ten or twenty meters. The Bouddica complex was enormous, almost a thousand feet long from one end to the other, counting both platforms and the bridge between them . . . but the sea transformed even the largest oil platform into a speck lost in emptiness. At night, the speck became harder still to find, especially if the SDV couldn’t use lights for fear of being spotted from the surface. Since they didn’t dare go active with their sonar to spot the thing, while passive sonar was notoriously imprecise, it was possible that they could spend hours aimlessly circling about, passing within a few yards of the objective and unable to see it in the darkness.

Not that it was a piece of cake pulling this stunt off in daylight. The murk ahead played tricks on the eyes, with the wavering shafts of sunlight from the surface creating the illusion of large and solid structures. As Johnson increased the angle of separation between the SDV and the Horizon, he began trying to pick up that rhythmic clanking he’d heard earlier. He was also keeping his eye glued to the compass bubble on his console. The Horizon had been lined up perfectly with Bouddica before the sub’s release. By watching his compass heading, his clock, and his speed, he could hold a mental image of the platform’s direction as the SDV changed course. Bouddica was—should be—that way.

He hoped. He glanced at his console clock. Though the exact timing was the subject of considerable guesswork—their speed through the water couldn’t take into account the speed of the water itself, and that could vary quite a bit with depth or position—it had been almost fifty minutes since their release from the Horizon . . . enough time, perhaps, to have missed the objective entirely.

He continued to listen for that intermittent clanking sound that had been, if not a certain guide, then at least a reassuring confirmation. It still seemed to be coming from more or less dead ahead. There were other sounds to contend with as well: the whirr and chug of some sort of equipment, probably a generator; the sharp, sudden, and unrepeated bursts of sound known to sonar operators as transients . . . caused by such unpredictable events as someone jumping off a ladder onto a steel deck, or dropping a heavy tool; and finally, the welcome throb of Horizon’s engines, backed down now to a gentle purr and interspersed with occasional blasts that sounded like steam hissing from a vent. That meant that the tug had come as close to Bouddica as the tangos allowed; her engines were running, and the sharp hisses were bursts from her fore- and aftmaneuvering thrusters. She was station-keeping and, in the process, providing a rough beacon for the SDV while SAS Captain Croft negotiated with the tangos.

Horizon’s engine sounds were well off to the right now and starting to pass astern. That suggested that he might not have passed the oil platform yet, but it must be getting damned close.

The operation was like a colossal, high-tech game of blind-man’s buff. And the stakes of this game . . .

Johnson didn’t want to even think about that.

And just when he’d begun assuming that the SDV must have missed the objective, that he would have to circle around and try another pass, the gray-lit backdrop of the water ahead seemed to take on a faintly more solid feel, a tenuous something that gradually formed a spiderweb of wavering shadows against shadows that was nonetheless more substantial than the light-shaft phantoms he’d been watching earlier. Banking slightly to the left, Johnson slowed the SDV’s forward motion to a crawl and steered for the apparition, which slowly solidified into a dark framework of struts and pilings, descending out of the silvery light of the surface and plunging into the black emptiness below. The bus was scant yards from the nearest of the pilings before any detail at all was visible, a dark and muddy-looking encrustation of algae, barnacles, and muck adhering to the surface of a vertical post four feet thick.

“End of the line back there,” Johnson said into his face mask mike. “We’re coming up on Bravo.”

“Good naviguessing, Skeeter,” Murdock’s voice said in his earphones. “Bang on the money.”

The skipper’s praise warmed him.

For the first time since he’d been transferred to SEAL Seven, Johnson felt like he belonged.