The dark, tepid Pacific water closed over Pitt's head; he momentarily allowed his body to go limp in the weightless dimension of the sea. The circular beam c from his dive light illuminated the diver twenty feet below, who was looking over his shoulder to see if Pitt was trailing his kicking fins. It suddenly occurred to Pitt that being last man in line might be dangerous. The suffocating blackness plunged him into a profound sense of anxiety; he was certain that every type of predator imaginable was sneaking into position for a quick bite of his legs. Every few seconds he spun around, flashing the light in all directions, but met no monsters of the night. The only odd-looking creature in his field of vision was his fellow human swimming unconcerned below.

Pitt's apprehension eased somewhat when the bottom loomed up through his face mask-for all he knew he might have been swimming upside down. The rocks took on morbid shapes with ghostlike faces, but they seemed like old friends when he reached down and touched their coa.r.s.e, solid features. A nervous squid, the first sign of sealife, dashed across his narrow angle of sight and vanished. Then the rock formations tapered away and the seafloor became sandy; Pitt's adrenaline surged through his body as a huge black shape rose up under the swaying concert of light beams.

The Starbuck lay just as he'd left her, looking like a great spectral monster in the blackness. Kicking his fins, Pitt swam past the Navy men to the head of the line and, grasping Giordino by the arm, peered into his friend's face mask. The face inside was softly distorted by the dive light but Giordino's eyes were bright and, in spite of the mouthpiece, his grin was clear and distinct as he gave a "thumbs up" sign.

Pitt wrote some words on his message board, motioned to Crowhaven, and held it up.

THIS IS WHERE WE GET OFF. SHE'S ALL YOURS.

Crowhaven nodded, his blond hair drifting in loose strands. He quickly began distributing his men: four submariners and one SEAL were to enter through the flooded forward torpedo compartment and close the vents and valves left open by the Martha Anns divers. The rest of the men were to drop througji the aft escape chamber into the dry section of the submarine and make their way to the control room.

The submariners' fear had left them now. The time had come for them to rely on their own skills and experience. The men forward entered in one group, but the crew aft had to divide into three shifts due to the chamber's compact interior. Pitt closed the hatch after the last five men dropped into the sub and waited until he felt the surge from the exhaust vents as the water was expelled from inside the escape compartment Then he pounded the b.u.t.t of his knife against the hull three times. Almost immediately three m.u.f.fled knocks came from inside, signaling no problems so far. Pitt swam along the narrow top deck to the bow where he repeated his poundings. The reply came back much slower this time with more of a muted sound due to the acoustics of the flooded torpedo room. Pitt wrote again on the board.

ENTRANCE AROUND SOMEWHERE. 18 MINUTES.

Giordino understood. Eighteen minutes of air; that's all the time they would have to search for the entrance to the seamount. Pitt tapped him on the shoulder and darted off to the right. Giordino followed Pitt's slithering form as they silently glided over the eerie seascape, bound together by the fragile glow of their lights. They didn't bother memorizing landmarks; instead they placed their trust in the compa.s.s strapped to Pitt's left wrist as the only means of rediscovering the Starbuck before their air ran out.

Their first encounter was with another victim of the Vortex, slowly materializing in the twin shafts of their lights. The plates on the side of the hull were smooth and clean, and there was no sign of weed growth; it was a fresh wreck. Pitt was at a loss; he had studied the list of missing ships and except for the Starbuck, no new disappearance had been reported in the last six months. How could a ship this size vanish without being reported overdue in port?

She was sitting upright as though she were still floating on the surface, refusing to concede her fate. They swam past the deserted decks and saw that she had once been a trawler, a large one. A pity, Pitt thought She was certainly a fine ship. The bulwarks gleamed and the superstructure fairly bristled with the latest design in electronic scanners and antennae.

So far, there was no sign of Delphi's men, but just to be on the safe side, Pitt gestured for Giordino to stand watch while he searched the bridge. Giordino waved a hand in acknowledgment, stationing himself at a bulkhead below the starboard bridge wing where he switched off his light and instantly melted into the black depths.

Pitt snaked through the open door of the wheel-house and into its ominous, cryptlike interior. He shined his light about, rooted to the spot by the strange surroundings. His eye caught an ugly transparent snake that wiggled across the ceiling and dissolved into an open vent, then another long reptilian form that slithered into a ceiling corner and then slowly meandered into the vent. The snakes were streams of his own exhaust bubbles that had risen to the top of the cabin before discovering an escape route to the surface.

Pitt didn't know what he expected to discover in the ship, but what he found gave him nightmares for many years to come. The charts, folding back and forth from the current, lay on the table, still firm to the touch as though they had been immersed just the day before. The spokes of the wheel were thrown out in a pathetic circle of despair, as if knowing that no hands would ever grip their contour again. The bra.s.s on the binnacle gleamed in the faint light and the compa.s.s needle still faithfully pointed toward some forgotten course, while the arrows on the telegraph were settled forever on the ALL STOP position. Pitt bent closer; something was out of loiter. The letters beneath the signal lever weren't printed in English. He studied them intently for a moment and then swam back to the binnacle, aiming his light at the nameplate screwed flush above the compa.s.s opening. His knowledge of the Russian language consisted of less than twenty words, but he could make out enough of the backward alphabet to decipher the ship's name: ANDREI VYBORG.

So the Russian spy trawler had found the Starbuck, Pitt reflected. Only to die and rest beside her, courtesy of Delphi and his pirates. Pitt didn't have time to reflect further. Just then something touched him on the back of his shoulder. Pitt spun around, beaming his light into the face of a man.

It was a face that was frighteningly unnatural and twisted with an unG.o.dly expression. The white blur of teeth shone through a mouth that was agape, and he stared unblinkingly out of one eye; the other eye was hidden by a small crab that had eaten itself halfway into the socket. The man swayed and motioned like a drunken scarecrow, his arms lifting and falling as if beckoning under the silent, unrelenting force of the current. The terrifying wraith hovered four feet from the deck and moved against Pitt who was rooted to the spot, frozen immobile at the sight Pitt savagely shoved the dead body away, watching it float toward the inner doorway of the wheelhouse where it dissolved into the curtain of black beyond.

There was nothing more to be seen or accomplished on the Soviet trawler. It was time to get the h.e.l.l out; there were only a few minutes left before he and Giordino would be on their reserve air.

Giordino was still standing his vigil under the bridge wing when he heard the sound waves off in the distance. He swam up to the wheelhouse and motioned for Pitt, who was just exiting, to douse his light Pitt complied; they both crouched below the port window, listening to the approaching whirr of an electric motor several seconds before the dim glow of a light came into view.

At first it looked like a strange, primeval creature, but as it neared, they could see that it was an underwater craft designed like a porpoise with a horizontal fluke on the tail for control Two figures sat astride the sleek mini-sub, the man in the front saddle steering, while his partner navigated from behind. A small propeller churned the water behind the rear stabilizer and pushed the two men through the depths at a pace of about five knots. The craft and its pa.s.sengers were headed directly toward the bridge of the Andrei Vyborg.

Pitt and Giordino pressed their bodies against the bulkhead beneath the window. It was too late to contain their breathing; they could do nothing but watch helplessly as their bubbles floated upward into the path of the sub. In a synchronized movement, they each unsheathed their knives and waited for the inevitable confrontation-the twin streams from their exhaust air were bound to give their presence away. The sub veered around the forward mast and approached the wheelhouse. It was so close now that Pitt could distinctly make out the small breathing units attached to the crew's chests. His grip on the knife tightened; he braced his body to spring through the doorway, hoping to get in the first thrust, knowing his small blade was no match for the projectile guns. The moment of suspense ended. At the last possible instant, the sub's bow tilted sharply upward, pa.s.sing through the bubbles and disappearing over the bridge. The sound of the motor slowly diminished. Almost immediately its light was lost to sight and seconds later the last beat of the propeller died away.

Giordino switched on his light and Pitt could see him shrug his shoulders in a questioning, baffled gesture. Then it slowly dawned on Pitt. The Andrei Vyborg had not yet belched all of her air pockets. Everywhere along the hull and superstructure small trails of air and oil mingled and rose in lazy spurts to the ocean's surface. Delphi's men had simply ignored all signs of bubbles, knowing that a sunken ship takes months, sometimes years, to expel its trapped air.

Pitt tapped his watch and pointed in the direction of the retreating mini-sub. Giordino nodded and together they swam over the ship's railing, dropped down to the seafloor, taking advantage of its grotesquely shaped rocks and vegetation for cover. As the dark hulk of the Andrei Vyborg receded behind them, Pitt threw her a last look over his shoulder. The Americans now knew the location of her grave, but the Russians, he was certain, would never be told where to find her.

Pitt's depth gauge readings began rising. He led Giordino up a slope on the seamount The water was cold, far colder than it should have been for this part of the Pacific. Their eyes strained the length of their light's rays, searching the bottom for signs of activity, but evidence that would betray the geometrical straight lines of human manufacture failed to materialize. There had to be an opening, Pitt thought The mini-sub must have come from somewhere.

They were past their time limit now. There was no chance of making it back to the safety of the Starbuck. They had no choice but to keep going until the air in the main tanks was nearly exhausted and then head for the surface in the impossible hope they might somehow be picked up before the concussion from the Monitor's missile crushed their bodies to pulp.

Suddenly Pitt noticed a change in the water temperature. It had become warmer, perhaps by as much as five degrees. At the same moment, a powerful current rolled across the slope, sweeping the sand into small swirling clouds, stretching the weed growth on a wavering horizontal plane. The sudden surge of the current thrust its invisible ma.s.s against the two men, thrusting them over the seafloor like Ping-Pong b.a.l.l.s in a hurricane. The vicious flow swept both men through a thrashing forest of seaweed, the fronds flaying their faces, leaving red lash marks across their cheeks and foreheads.

Pitt somersaulted and collided with a huge outcropping of rock that was coated with a thick blanket of marine growth. The green slime rubbed off in his hands and the sharp edges from a colony of sh.e.l.l creatures sliced into his rubber wet suit. He was pinned against the rocks for an instant, and then the unpredictable whim of the current jerked him back into its path. He felt something grasp his leg. It was Giordino's arm, circled around Pitt's thigh just under the crotch, holding on with all the force of a hydraulic vise.

Pitt looked into Giordino's face mask and he could have sworn he saw one brown eye wink. The added weight of their combined bodies was already reducing the drag from the current, and more important, Giordino's grip would keep them from becoming separated during their swirling journey through the tempest of exploding sand and seaweed.

Pitt became aware of a dull clanking noise. An odd tolling sound coming from his airtanks smashing against the rocks. He tumbled on his back for a fleeting moment and shined his light upward, briefly watching the surface shimmer back in the reflection. He reached out as if to touch it and then realized that his mind was wandering. He jerked his senses back to the moment just in time to throw up his arm and shield his face before ramming a ma.s.sive barnacle-coated boulder.

What rescued him in those first jarring seconds was the quarter-inch rubber thickness of his wet suit But it wasn't enough to save him completely. The barbed growth cut past the rubber and nylon inner lining; Pitt was stabbed with pain as the water around his arm burst into a cloud of his blood. His face mask was ripped away and the swirling sand invaded his eyes and nostrils, scouring the delicate membranes. He tried to exhale through his nose to clear the sand, but only succeeded in adding to the irritation. His eyes stung from the combined attack of sand and salt.w.a.ter; the sudden closure of the lids threw his brain into spinning blackness.

Then his head slammed into a low rock and a skyrocket soared and burst into a brilliant rainbow of color, sputtered out, and all was still.

Giordino felt Pitt's body go limp and collapse; the dive light dropped from an open hand and fell to the bottom. Giordino shone his own light into Pitt's face, perceiving the loss of consciousness. He satisfied himself that Pitt's mouthpiece was still secured between the teeth and then tightened his stubby arms around Pitt's leg and continued hanging on.

A stretch of sandy gravel pa.s.sed under Giordino; he lashed out with his feet, desperately attempting to drag them as a brake. Both his fins were torn away and the skin flayed from his feet and ankles. He clenched his teeth on the mouthpiece of his airhose until the rubber split, and dug his bleeding feet deeper into the sand. It was a move born of desperation, and it failed. His feet merely gouged two grooves in the yielding sea bottom before losing their hold and breaking loose.

Suddenly, like a cat who tires of a mouse, the treacherous undercurrent spun them out of its mainstream and released them. Giordino quickly reached out and grabbed a handful of seagra.s.s, pulling his unconscious burden toward a small, craterlike pocket on the bottom. Then he relaxed and drifted downward in the calm water, letting Pitt sink gently beside him.

It was quiet in the operations bunker at Pearl Harbor. The typewriters were mute; the computers sat silent and inoperative, their tape reels staring like great round unlidded eyes. Half the staff was grouped around the radio center, the men thoughtfully smoking and saying nothing, the women nervously pouring coffee, looking pale and drawn. The tenseness in the atmosphere lay heavily and drained everyone's energies. Hunter and Denver sat on either side of the radio operator, looking at each other through tired, bloodshot eyes.

Denver pulled a small plastic vial from his breast pocket and idly toyed with it, rolling it back and forth on the table. Hunter studied him for a moment and then raised his eyebrows questioningjy.

"What's that thing?"

Denver held it up. "Pitt gave it to me to have a.n.a.lyzed. It was originally in a hypodermic syringe."

"Pitt gave it to you?" Hunter persisted. "What's in it?"

"DG-10," Denver said briefly. "One of the deadliest poisons around. Extremely difficult to detect The body has all the appearances of a heart seizure."

"What was he doing with it?"

Denver shrugged. "I'don't know. He was very sly about it Said we'd know in the end."

Hunter's eyes were remote, unseeing. "An enigma, that man's a don't-give-a-d.a.m.n enigma..."

"Telephone, Admiral."

Hunter was interrupted by an officer who held out a receiver. "Who is it?"

The officer looked lost for a moment, then hesitantly said: "It's Aloha Willie, the late night disc jockey on radio station POPO."

Hunter's mouth dropped. "What is this, mister? I'don't want to talk to any d.a.m.ned disc jockey. How did he get on our private lines anyway?"

The officer looked extremely ill-at-ease. "He said it was urgent, sir. His contest riddle is: the Blackbird has come home to nest He said you'd win a prize if you knew the answer."

"What nonsense is this?" Hunter fairly exploded. "You tell that nut to..." Suddenly Hunter's lips froze and his eyes widened. "My G.o.d, Crowhaven."

He s.n.a.t.c.hed the receiver and talked rapidly with the voice on the other end of the line. Then he thrust the receiver back at the stunned officer and turned to Denver.

"Crowhaven is sending over the frequency of a Honolulu radio station."