'It's not coming right at us. It should pass us about eleven hundred metres off the port bow.' The duty officer repeated the message to the captain. They listened, ummoving, as the sound peaked and then diminished slightly with a perceptible change in pitch. Washington noted its passage through the ship's depth level, headed for the surface.

Abruptly the noise ceased, to be replaced with an almost painful silence as saturated ears tried to adjust. Active dials lapsed into quiescence and the bright blip on the screen disappeared. Washington swivelled in his chair to exchange wide-eyed looks of surprise with the duty officer who reported once more to the captain.

Washington returned his attention to his instruments. Ten, fifteen seconds went by. Slowly he turned up the sensitivity of the device and the volume on the speaker and earphones. Only the routine sounds of the sea issued. After twenty-five seconds the duty officer still stood with the phone clamped in a sweaty hand, but others in the cabin began to shuffle in relief. Washington increased the gain a bit more and concentrated his trained ear to detect any hint of abnormal sound. He systematically switched display modes but found no clue to the thing that had just assaulted them.

With the suddenness and impact of a physical blow, the cabin filled with the sound again. Washington shrieked, ripped off his earphones and slapped a palm over each ear. He slipped off his chair and knelt in a daze of confusion, his body pumped with adrenalin, his ears ringing with an intense hollow echo. Several figures rushed to the sonar console. Two friends bent to Washington. Someone fumbled, then found, the volume control. The frightening hiss dropped to a muted roar and the duty officer was left in the new quiet, shouting hoarsely into the phone.

The noise dropped gradually, and then just before it faded below a perceptible level it ceased abruptly once more. Silence fell in the cabin, broken only by the chatter of the sonar and the quiet moan of the man who remained on the floor, rocking gently, his hands over his ears and his eyes squeezed shut.

Several days after the cancellation of Project QUAKER, Isaacs played a closely fought game of handball with a friend and colleague. Captain Avery Rutherford, one of the senior officers in Naval Intelligence. Rutherford was three years older than Isaacs, but in excellent shape. They split the first four games and went to a tie breaker on the match game. Isaacs scored once and served at game point. After several volleys, Isaacs took a shot in front court. Calculating to catch his opponent off guard, he hit the ball softly to the front wall, but it went a bit too high and gave Rutherford time to cover it. With Isaacs in the front court, Rutherford played a favourite shot which came off the front wall as a lob calculated to land in the rear corner, a troublesome left hand return at best. He then retreated rapidly to centre court just behind the service area to await the return, hoping to hear the satisfying silence of a missed shot.

Isaacs knew the other man's tactics, however, and back— pedalled furiously to cover most of the distance to the left rear corner before the ball left the front wall. This gave him time to plant his feet firmly, eye locked on the descending sphere. The ball bounced on the floor, then off the back wall, nicely clearing both it and the side wall. Isaacs made the shot at hip level, putting into it everything his weaker left hand could muster. The ball rifled cross court, just missing Rutherford 's left knee. It struck almost dead in the corner, the from wall a fraction of a second earlier than the right, two inches above the floor. It skittered once and then meekly rolled across the court to bump gently into Rutherford 's toe.

The sudden denouement caught Rutherford by surprise and he just stared at the ball. Then he scooped it up and turned.

'Damnation, Bob, that was a hell of a shot!'

'Thanks,' Isaacs grinned. 'Amazingly enough, that's just what I wanted it to do.'

They played two more games for exercise, but without quite the fire. Isaacs took the first by a comfortable margin, Rutherford the last.

After the game, they left sweat-sagged piles of gym clothes in front of their lockers, grabbed their towels and stepped into the steam room. They sat on the bench and rehashed their play, each enthusiastically recalling the other's good points and mixing in an occasional soft-pedalled critique.

They fell silent for a couple of minutes. Then Rutherford swivelled his head and looked at his companion.

'Do you mind a little shop talk, off the cuff?'

Isaacs leaned back against the wall, his eyes closed.

'Of course not, what's on your mind?'

'Well, we've had scattered reports of a strange acoustic phenomenon, sort of an underwater sonic boom. This thing's been kicking around. Nobody's done anything about it because no one knows what to make of it. I just wondered whether it might ring a bell with you?'

'No,' said Isaacs lethargically, 'I haven't heard anything about it. We've been up to our ears counting screws and bolts in Tyuratam, waiting for them to launch the other shoe. Some kind of explosion?'

'No,' Rutherford shook his head and pinched some sweat out of his eyes, 'it's not localized like that. Something seems to be moving through the water, making a hell of a racket as it goes. It comes from the ocean bottom and apparently disappears momentarily at the surface. Then, it reappears and proceeds back down to the bottom.'

'Some kind of missile, torpedo?'

'Seems like it, doesn't it? But there's no indication of any launching craft. Besides this starts from really deep down, miles.'

'How about an underwater volcano, maybe spewing out blobs of lava, or rocks?'

'There's probably too much drag in the water for that to be possible, but I'd give some credence if the reports were from one spot. They're not, though. They're from all over the globe. Several from mid-Atlantic shipping lanes, a few near Japan, a couple from the Sixth Fleet in the Med, one south of Madagascar, another in the Sea of Tasman between Australia and New Zealand. The latest one came from a sub north of Hawaii , that's why it's on my mind. A particularly close call, poor bastards thought they were being attacked. Anyway, the thing seems 'to hop all over.'

The men fell silent. Rutherford leaned over to examine a chipped nail on his big toe. Isaacs had not really been concentrating on the conversation. Now snippets of it rolled around in his head. Suddenly, a surge of adrenalin went keening out of his belly and through his body. His eyes snapped open and, despite the heat, he felt as if someone had just raked a large icy comb down his back.

He sat up and faced Rutherford who still bent over his foot.

'Those reports you just described, they seem to be either north or south of the equator, about equal distances.' He tried to keep his voice casual.

'Oh yeah, I forgot to mention another curious feature. This thing appears at random times, not always near the same latitude, sometimes north, sometimes south.'

'Thirty-three degrees.'

Now Rutherford swivelled his head in surprise.

'Hey, friend, you've been holding out on me!'

Nervous energy drove Isaacs off the bench. 'Nothing like it,' he said intently, 'just slow to make the connection.' He paced the small room randomly, oblivious to his steamy surroundings, his mind racing. 'Good lord, in the water, too! What the hell does that mean?'

Rutherford had witnessed his friend's burst of intensity before and, failing to understand what had set him off, watched bemusedly as Isaacs moved about, his cock flipping drops of sweat and condensed steam at each sudden turn.

Isaacs stopped in front of him.

'Up to last week we were analysing the seismic equivalent of your phenomenon. Something's moving through the earth, generating seismic waves.'

He sat suddenly next to Rutherford and continued.

'I had some of my people keeping an eye on it, even though we didn't know what to make of it.'

Then he was thinking out loud.

'The seismic data only told us what was happening in rock. I convinced myself that whatever it what was confined to the earth's crust, that the seismic waves were its essence. Now you tell me something about it continues into the water.' He shook his head. 'I don't like it. I don't like this at all.

'Listen, we've learned some things you apparently haven't stumbled onto yet. This thing is always there, and very methodical. It just goes back and forth, back and forth, always on the same path through the earth.' He waved his arms. 'And then out into the ocean! Shit! No reason to think it doesn't continue into the atmosphere! No telling how far it goes.'

He leaned back against the wall. 'Our problem is that McMasters scuttled our operation, claimed it wasn't Agency business.' He paused for a moment. 'Damn, it's hot in here! Let's go someplace where we can do a little serious talking. Better make it your office, since the subject is officially verboten on my turf.'

As Rutherford steered his staff car through the prerush hour traffic, Isaacs explained animatedly how his interest in the seismic signal became aroused during his duty at AFTAC. He then outlined the progress Danielson had made, culminating in her conclusion that the phenomenon followed a trajectory fixed in space. They finished the drive in silence while Rutherford ruminated on this new information.

A half hour later they entered Rutherford 's office. Rutherford ordered up the Navy file on the acoustic phenomenon. He sat behind his desk while Isaacs remained standing, rocking nervously on the balls of his feet. Rutherford spoke first.

'Boy, I'm really having trouble absorbing this. I had a notion of a random, infrequent occurrence, and now you describe something punching through the surface like clockwork, every eighty minutes or so. I guess I still don't get the picture. Tell me again how this fixed motion works.'

'Let me use this globe,' Isaacs said as he lifted a fancy relief model of the earth off its shelf and put it on Rutherford 's desk. He grabbed a pencil and held it pointed towards the surface of the globe, about a third of the way above the equator. 'The thing always moves along a line, like this.' He moved the pencil in and out, parallel to itself, 'Zipzip, zipzip. But as the earth turns,' he spun the globe slowly with his free hand, 'the thing always comes up in a different place.' He tapped the pencil rhythmically as he spun the globe, each tap hitting it an inch further on than the last.

'Let me see that,' said Rutherford , reaching for the pencil. He held it alongside the globe so that he could project it in his imagination into the centre of the globe. Then he moved it back and forth along its length as he spun the globe slowly, eraser to the northern hemisphere, then point to the southern, eraser to the north, point, south. 'Okay, I think I get the picture, but what could possibly do that? Through the centre of the earth? Jesus Christ!'

He jerked his head up as a knock sounded at the door.

'Come in.'

An aide came in bearing a file folder.

'Bob, Lieutenant Szkada. Lieutenant, Bob Isaacs, Central Intelligence.'

Isaacs nodded at him.

'Sir.' The young man placed the folder on Rutherford 's desk.

'That'll be all,' Rutherford said to him with a note of paternalism.

'Yes, sir.' The lieutenant turned and left.

'Sharp young man, that,' Rutherford confided. 'My right arm.' He pulled the file towards him. 'Let's see what we have here.' He extracted a list of reported detections and banded it to Isaacs. Rutherford leafed through the corresponding write-ups, looking for ones that were not hopelessly sketchy.

As Isaacs scanned down the list of sonar reports, he let out a loud exclamation.

'I'll be damned!'

'What?'

'One of life's little ironies. Several of these reports are from the undersea arrays of acoustic monitors.'

'Sure, we have those babies all over, bound to pick up something like this. So?'

'That system is also operated by AFTAC. The whole ball of wax was right under my nose, both seismic and sonar data. I'm kicking myself, I was so hung up on the seismic signal propagating through the earth. I had my people trying to put together a puzzle with half the pieces missing.'

Isaacs threw the list on the desk and pulled a chair around beside Rutherford. They spent fifteen minutes checking the tune and position on earth for each of the reports and converting that data into a projected position on the celestial sphere, to see what stars were overhead. As near as they could tell, it was always the same patch of stars. All the sonar events fell on the path predicted by the seismic data. Trying to estimate whether the influence was precisely at the phase which brought Danielson's seismic signal to the surface was more difficult, but the evidence they had seemed damning enough.

'So what did you say you are doing about all this?' Rutherford wanted to know.

'Not jackshit.' Isaacs described his skirmish with McMasters.

When he finished, Rutherford inquired, 'Can't you get McMasters to reopen the file, now that you have this confirmation from our data?'

'I doubt it.' Isaacs frowned in concentration and rubbed his prominent nose. He got up and paced the room. Post handball thirst nagged at him. He wished he had a cold beer.

'You've told me something new. The source of energy driving the seismic waves somehow proceeds into the ocean. That banishes my lingering suspicion that we were dealing with an ordinary, if highly regular, seismic phenomenon. But we're no closer to understanding what's really happening. Without a more substantial change in the situation, McMasters would stand to lose face if he backs down. I've got to have something beyond the fact that this thing is amphibious before I can go back to him and convince him to reopen our investigation.'

He crossed the room twice more, thinking.

'He's right that there's no obvious reason to consider this Agency business. But dammit! It's got to be somebody's business.'

Rutherford rubbed his chin. 'Is this thing dangerous?'

Isaacs stopped pacing and faced the man seated at the desk. 'Not clear, is it? Whatever it is, it makes a lot of noise that travels through rock and water. But noise alone doesn't make it dangerous.' He resumed his pacing.

'The scary part is that something is moving through that rock and water, making the noise. We haven't the faintest idea what. That doesn't make it a threat, but it sure as hell makes me nervous!'

Rutherford leaned forward on his desk, watching Isaacs perform his epicycles. 'Listen. Your seismic data were ideal to track this thing over large distances coherently and establish that it moves along a fixed direction. But with your hint of where and when to look, our sonar detections should give a higher precision. We could put a ship right on top of it and find out what we're actually up against.'

Isaacs sprawled stiffly in a chair, as if he might leap out of it again at a moment's notice. 'Actually, we could do something like that on land, too, if McMasters hadn't tied my hands,' he responded. 'You're right, though, you're in a position to proceed, and I'm not.

'There is a practical point,' Isaacs continued. 'As it stands now, you don't formally have enough information to move on your own. You need our knowledge that it behaves in a systematic way.'

Rutherford nodded his assent.

'But I can't give it to you officially because of this roadblock McMasters has thrown up.'

Isaacs smiled and leaned forward in his chair. 'I think you're going to have to wake up in the middle of the night with a sudden insight. Your past brilliant record would presage such a breakthrough.'

Rutherford gave an exaggerated 'aw shucks' gesture. 'Actually, it might be better if it didn't come directly from me. McMasters knows we're friends, and he might fit things together and give you a hard time for leaking information. I think I can handle it so that one of my associates has the inspiration.'

The two men grinned at one another and then lapsed into a contemplative silence. After several minutes, Rutherford stirred and walked over to a window and looked out.

He turned and asked, 'What in hell are we getting into here, Bob?'

Isaacs returned his look, unspeaking.

Rutherford continued, 'I keep coming back to the fact that this flung is locked to a fixed direction in space. That must be a crucial hint. And the fact that it moves easily through solid earth and miles of water. What does that mean?' He turned to the window again, anxious to express disturbing thoughts, but subconsciously unable to face his friend at the same time.

'You know the image I get? A beam. A beam of some kind, focused into the earth and playing back and forth.'

He turned suddenly, angry at a situation that departed so profoundly from his experience, forcing him to strange, uncomfortable extrapolations.

'Damn it, Bob, you know I'm a hard-nosed, practical man. But don't we have to face up to the idea that something is out there? Doing this to the earth?'

Isaacs ground his right fist into his left palm. 'I confess, Av, when I first heard about the selective orientation in space, I found myself toying with such a notion. I put it out of my mind as idle fantasy. Now I don't know. I do know the more I learn about this thing, the more scared I am.

Avery Rutherford stood next to the captain of the USS Stinson and gazed out across the ocean as it reflected the early morning sun. Rutherford delighted at being able to spend these long days of mid-June where he loved to be the most. His job was challenging and important, but it kept him behind a desk far too much. He had grown up in boats of all sizes in the waters off Newport and the only time he felt fully alive was at sea. A hectic week had been required to feed Isaacs's hint to his aide, Szkada, then to work up a plan and arrange for the ship, but it was worth it. Rutherford felt great!

The captain barked commands as they closed on the chosen position. Finally, the trim craft lay dead in the water, and they waited and watched and listened. The ship, a Spruance class destroyer, was designed for intelligence work and bristled with sophisticated tracking and detection devices. At last, word came up from the sonar room that their target had appeared, moving incredibly rapidly, headed for the surface in a scant thirty seconds. Rutherford gritted his teeth and framed his field glasses on the water a thousand yards away where they had calculated the influence would reach the surface.

The sonar data were automatically fed into the ship's computers to plot the trajectory. He listened to the tense messages on the intercom from the sonar room, the voice clipped, rapid, hurrying to keep up with something moving too fast. The new prediction showed the point of surfacing to be several hundred yards further from the ship than originally estimated, but still very close. Ten seconds. Rutherford felt a knot of tension as beads of sweat grew on his forehead. He tried to keep his mind neutral, but an image kept intruding, that of a ray guided by an unseen hand. He could sense that ray arcing through space like nighttime tracer bullets, then cutting a swath through the earth.

Over the intercom came the tinny squawk as the sonar operator counted down the time to contact with the surface:

'Five.'

'Four.'

'Three.'

'Two.'

'One.'

Rutherford held the binoculars tightly to his face, the magnified image of the water welded in his brain. He braced himself for the shock, either physical or mental.

'Zero.'

Nothing.

Absolutely nothing happened except for a small splash at the margin of his field of vision. Then he blinked and even that was gone. Faintly over the water a strange hissing carried, but that, too, quickly faded.

Rutherford and the captain exchanged amazed looks.

The captain punched a button on a console.

'What have you got?'

'Nothing, Captain, it's gone,' came the negative reply. He turned to Rutherford.

'If it's like the Seamount event, sonar should pick up something going down after some delay.'

Rutherford nodded.

The sonar man had been alerted not to increase the gain on his instrument in the interlude.

Again came the faint hiss. Rutherford raised his glasses too late to see a second rise of spray some distance from the first splash.

'Whup! There it is!' came the report of reacquisition from the sonar room. They listened as the relayed reports followed the acoustic noise to the sea bottom far below.

Rutherford spent the next two hours in the computer room overseeing the analysis of the tapes of the sonar signal. His examination of the previous underwater events suggested to him that the phenomenon did not move along precisely the same line. This data supported that view. There was a certain erratic behaviour superposed on the basic fixed direction of motion. They would never be able to tell exactly where and when the surfacing would occur. He thought to himself, so your aim's not perfect, you bastards, and took some satisfaction in that.

The estimate of the next nearest surfacing was refined on the computer and Rutherford reported that to the captain. After some discussion they agreed that for all the furore underwater, whatever it was seemed to lose potency at the surface. They agreed to get as close as possible to the next event. The destroyer headed for a spot about a hundred and ninety miles west which, in a little more than twenty-four hours, would fall along the right path at the proper phase so that the phenomenon should approach the surface.

They arrived in late afternoon and spent the remainder of the daylight hours cruising the area obtaining comparison data on the sonar background and checking for anything which could represent a precursor to the expected event. There was none.

Rutherford turned in early. He spent a restless night and dropped into sound sleep only shortly before daybreak when a young crewman awakened him.

Two thousand miles west of where the Stinson made slow circles in the mid-Atlantic, Robert Isaacs roused from a troubled sleep, carrying his dreams with him. He was watching the tops of the heads of figures as they roamed the flat terrain of satellite photos. One figure tried to turn its face upward to be recognized. Isaacs could feel the strain of its effort, and head swivelling backward, the forehead tilting upward, upward, upward, but never enough to reveal the face.

Then, there — Not a Russian! Rutherford !

Isaacs jerked awake, staring at the ceiling, his pulse racing. His twitch disturbed Muriel. She snuggled over to him, cupped a bleep in her hand, and pushed her nose into his shoulder.

'You all right, honey?'

'Uumph. Just a dream.' He turned towards her and threw a comforting arm over her hips. Soon she was breathing deeply again. He lay awake, slowly relaxing back towards sleep. Rutherford Ship Water Sonar.

The Novorossiisk!

This time he sat bolt upright. No dream. Dear god! How could he be so dense? The Novorossiisk was so long ago, succeeded in his attention by the attack on FireEye, the shuttle mission, the feverish developments at Tyuratam. But this had to be it! The Novorossiisk had been in the Med, near thirty degrees latitude. The Seamount had reported something going up and something going down. Rutherford had radioed the same behaviour yesterday. The Novorossiisk had reported something going down. Why not up? Lost in the shuffle? Who knows? Must check that out. Was the Novorossiisk in the right place? Check that out. Oh goddamn, Rutherford said he was going to sit right on

He rolled out of bed.

'Bob?'

'I think Av Rutherford is in danger. I've got to make some calls.'

'Do you want me to get up?'

'No, that's crazy; you've got to be fresh in court at nine.'

He pulled on some sweatpants in lieu of a robe and fumbled out the door to the stairs. In the kitchen he blinked in the glare as he tripped the light. He punched the familiar number into the phone, missed the next to last digit in his bleariness, swore, and punched it again. He requested the night radio operator to call him on a secure line. As he awaited the call, he grabbed a note pad and tried to figure out if the Novorossiisk had been right on Danielson's magic trajectory. He was still too befogged and the numbers too cumbersome. But it was plausible. Too plausible! This thing they chased not only moved through the earth and oceans, it punched holes in ships!

As he stared at his scribbled notes on the pad, he slowly became aware of the smell of fresh coffee permeating his nostrils. He looked up to see Muriel fetching cups and saucers out of the cabinet. She caught his mixed look of guilt and irritation that she should be up tending to him and headed him off.

'I can use an early start, too. I need to polish my strategy.'

Her husband still looked disgruntled.

'Besides,' she continued, 'if I beat my minions in to work on a Monday morning it will fire them with such defensive zeal that we'll just blow the opposition out of court.'

Isaacs smiled wanly at this image and rose to hug her from behind.

'All right, counsellor, you win. Let's have some coffee.'

He broke off his embrace suddenly at the sound of the telephone, whirling to grab it in mid ring. He sat and hunched over the receiver as if to make it part of him.

'Hello? Yes?' He repeated a sequence of code numbers. 'Right. I want you to patch a call through the Navy. Top Priority. For Captain Avery Rutherford on the Destroyer USS Stinson. It's on patrol in the Atlantic. Yes, I know what time it is. What's a satellite link for? It's two hours later on that ship. Yes, I understand, but this is extremely urgent.' He glanced at his watch. 4:38. Nine minutes until contact. 'Yes, I know you will. Yes, immediately please. Thank you.'

He hung up the phone. 'Problem?'

'Not in principle, it's just that our vaunted instantaneous satellite communication net is designed to function from various war rooms, not from cosy Georgetown kitchens.'

He lapsed into tense silence, glancing at the coffee pot, his watch, the phone. Time dragged slowly. After an excruciating interval, the coffee maker stopped gurgling, sighed its readiness. He looked at his watch for the tenth time. 4:40. Seven minutes. How long would it take to move the ship if they did get through? Several minutes? When would it be too late? He did not look up when Muriel put the coffee in front of him. He took a few sips and then watched it steam away its heat, its life force. 4:44. Three minutes, probably too late, anyway. He felt ill.

The phone rang. He jerked the receiver to his ear.

'Mr Isaacs?'

'Yes!'

'I've got the Stinson. They're looking for Captain Rutherford. Will you hold on?' 'Yes, of course. He'll be on the bridge.'

Isaacs could hear the operator relay this message to the radio man on the Stinson. Then he spoke to Isaacs again.

'Bit of a crunch there, sir. They seem to be in the middle of an operation.'

'Yes, I know.'

There was a long pause.

'Sir?' The voice sounded worried.

'What is it?'

'There seemed to be some kind of ruckus there, and then I lost contact.'

'You what?'

'I'm sorry, sir. I lost contact with the Stinson.'

Isaacs remained silent a long moment.

'Sir?'

'Okay. Try to get them back. Call me when you do.'

'Yes, sir.'

Isaacs hung the receiver on its wall cradle and then slowly lowered his head onto his hands. Seated next to him, Muriel reached a hand to his bare shoulder, her face drawn with concern.

The sea lay calm and the rising sun burned along the gentle swells.

The routine of the previous session repeated. Rutherford took a position on the bridge and stood checking the liquid crystal digits as they swapped on his watch. As the time counted down to scarce minutes, an orderly stepped onto the bridge.

'Captain Rutherford?'

Rutherford swivelled to face the young man.

'Yes? What is it?'

'Sir, you have a call on the radiophone.'

'I can't take it now! Tell them if it's important to hold on for a few minutes.'

The orderly sensed the tension and stepped back against the bulkhead to watch as Rutherford turned to scan the ocean. Within seconds of the predicted time, the sonar room reported.

'Here she comes!'

Allowing for the inaccuracies in the calculations, Rutherford had stationed the ship precisely at the point where surfacing was most probable. These inaccuracies plus the intrinsic meandering of the position convinced him they would be very lucky to be within several hundred yards of the event. He hoped they would be able to see something to help clear up the mystery.

'Coming straight up! Right underneath us!'

Just so, ruminated Rutherford. At great depths, small lateral offsets in position were difficult to detect. On his watch, the minute digit shifted up by one. Ten seconds.

'Two thousand metres!' squawked the sonar room link. 'Uh, Captain? It's still headed right for us!'

In a corner of his mind, a thought began to dawn on Rutherford. Maybe they had been too brash, forsaking a second distant observation. Our measurements aren't exact, he thought, the thing does wander a little erratically. How confident can I be that our best estimate is wrong, that it will surface nearby, but not exactly where I predicted? What if the small random motion just offsets our position errors and we are correct by blind luck? Even worse, what if many periods are required before the random motion causes an appreciable change in the position of surfacing? Suppose over the small time span since the last event there has been negligible change and my predictions are precisely correct?