"He said "contingent," not "contagious.""

FitzHugh looked at Danny. "I should have said that history is a chain of cause-and-effect," he said.

"One event leads to others, and then to still others. Often, great events hinge on small occurrences."

Wilson Cartwright, a history professor at the University, spoke up from the booth behind fitzHugh.

"That"s gospel truth. In 1862, a Confederate courier lost a copy of Lee"s troop dispositions. Two Union foragers found them and McClellan managed-barely-to win the battle of Antietam, which gave Lincoln the opportunity to issue the Emanc.i.p.ation Proclamation. And when the news of the Proclamation reached England, the cabinet reversed its decision to intervene on the Confederate side. In consequence of which..."He lifted his drink in salute to the bar. "...my great-grandpappy became a free man."

Hennesey nodded. "Da met me Ma in the same way. Another small chance-though the outcome was not so momentous as war and freedom. He was on the run-. This was during the Troubles, when the Big Fella and the Long Fella had their row-bad cess to "em both-and Da, he found himself in on the wrong side. O Daugherty, you know what I"m speakin" of, and enough has been said about that. Da took himself to the Waterford hills and, finding himself at a crossroads, tossed a coin. The shilling sent him to Ballinahinch, where me ol" Gran was keeping a pub in those days and Ma waited tables. Now Da was not the man to pa.s.s a pub without a drop of the creature, so he stopped and..." The man"s long, doughy face turned a deep red. "...here I am. Had the shilling read tails, he was a dead man, for his enemies were waiting down the other road. As it was, what with one thing and another..." And he pointed with his drooping chin to the photograph on the wall opposite, where a far younger Hennesey and O Daugherty stood side by side in black-and-white, stern-faced splendor, arms crossed and legs akimbo before the newly opened Irish Pub.

Doc Mooney raised his pint. "I have always thought you an unlikely man, Hennesey."

"But that"s just the point," fitzHugh said. " Everything is unlikely... and therefore fragile."

" "Fragile," " said Himself. "A curious word."

"Fragile," said fitzHugh with an affirmative nod. "Because the slightest b.u.mp and....You see, the quantum foam is subject to sudden, spontaneous disturbances. These create "probability waves" in the continuum that propagate down the time stream creating a new past. The old past is obliterated. As it was in the beginning, is not, and never more shall be."

Himself scowled a bit at the altered quotation, but Danny Mulloney brightened, which is always a bad sign. "Do you mean to say," he said. "Do you mean to say that all those dinosaur fossils and such might have been put in the ground only a few thousand years ago?"

FitzHugh blinked and looked thoughtful. "Certainly, it"s conceivable," he said slowly. "Yes. Suppose that evolution originally followed a different course-perhaps those strange Burgess Shale creatures I"ve read of won out over our own familiar phyla, and after a time strange things stalked the Earth of sixty million years ago-things that never held the promise of man. Then, a bubble bursts in the foam and a probability wave ripples down the timeline-and now dinosaurs leave their bones in the mud instead of things with no names. So, yes, in one sense, this new past could have been laid down a few thousand years ago; but in another sense, once it had been laid down, it had always been there."

Danny pursed his lips, for I do not think he had envisioned a different evolution when he raised his question. Meanwhile, a ripple of wisely nodding heads showed the incomprehension propagating around the oval bar. FitzHugh noticed and said, "Perhaps a sketch will clear it up." He seized a napkin andimmediately began to doodle on it. Sitting as I was on the far side, I could not see what he sketched and Hennesey, noting my frustration, waved me inside the Sacred Oval. "Here," he said, handing me a bar ap.r.o.n. " "Tis a busy night and we can use the help." Then he set off to the front end of the bar to tend to the raging thirst there.

Tying the ap.r.o.n, I stepped across in time to hear fitzHugh say, "This was the continuum in its original state." I glanced at the napkin and saw he had written: "Then, a quantum disturbance alters event A to event A*. A stray chronon-a quantum of time-emitted from the foam, strikes like a billiard ball." He turned to Dr. Cartwright, who had left his booth to stand behind him. "Perhaps your Confederate courier, Wilson, doesn"t drop his packet." He held up the napkin again.

The big historian looked thoughtful, and nodded. Maura Lafferty, who had also joined the little group at the back end of the bar, leaned over the man"s shoulder. "Why did you add the "D"?"

"Oh, time doesn"t stop just because there is a bit of redecorating going on," fitzHugh said. "The present is... call it the "bow wave" of the Big Bang, plowing through formlessness and leaving time in its wake. But behind it is coming the "bow wave" of the new version, altering all the original consequences of A. When the wave front reaches B, event B "unhappens." Something else-call it G-happens instead."

"Why G?" Danny asked, frowning over the sketch. "Why not call it B?"

"It doesn"t matter what he calls it, ye spalpeen," said Doc Mooney.

FitzHugh grimaced. "Actually, it does. I don"t want to imply that B happens differently -because it might not happen at all."

Cartwright bobbed his head. "That"s right. If McClellan hadn"t intercepted Lee"s orders, it wouldn"t have changed the outcome of Antietam. There wouldn"t have been a battle at Antietam. McClellan only attacked there because he had Lee"s orders. Without them, there would have been a different battle at some other time and place."

I scratched my head. "So why didn"t you alter C, D and E?"

"Because the wave front hasn"t "caught up" to them yet." He busied himself at the napkin. "Here, this is then next quantum of time, the next parasecond."

"You"ll notice that the original causal chain is still propagating itself, and event E has led to event F.

But the revision is catching up. Change waves move faster than one second per second-just as water moves faster down a channel already dug than it does across virgin ground-but you really need two different kinds of time to talk about it intelligently. Eventually, the change wave reaches the present, merges into the original Big Bang wave, and the revision is complete." He held the napkin up one last time.

"Even our memories are reconfigured," he said. "The right ripple and... who knows? We might be sitting here discussing Lee"s victory."

"You might be," said Cartwright dryly.

Doc Mooney rubbed his chin and frowned. "I see a problem," he said. He spoke with a chuckle, as if he suspected his leg of being pulled. "If our memories are reconfigured, how could we possibly know the past was ever different?"

The shadow pa.s.sed over fitzHugh"s face once more. "Normally...we wouldn"t."

Doc Mooney slapped his forehead. "Now, I am an old fool. I had started to put the jawbone into my jacket pocket, then I laid it back on my desk." Defiance flashed. "And it has been sitting back there in the lab, all along," he insisted.

FitzHugh nodded with solemn fish-eyes. "Yes. Though perhaps not "all along." If at the very moment you laid the jawbone on the bar, a change wave "caught up" with the present, you would have for a bare instant two conflicting memories. A fragment of the original memory can survive and you sit here at "L"

remembering a bit of "F," instead of "K." The French have a word for it..."He snapped his fingers, searching for the word.

"Merde?" suggested Doc innocently.

"Deja vu?" said Maura.

FitzHugh shook his head. "No. Deja vu is when the change wave does not affect your own personalhistory, so instead of a fossil memory, you have an instant of remembering the same thing twice." He looked at each of us, and it seemed to me that his eyes held immeasurable loneliness in them. "That"s why these phantom memories almost always involve trivia." He shrugged, looked off at the corner. "Only an idle fancy. Who can say?"

Himself lifted fitzHugh"s now-empty mug and cradled it in his hands. He gave the physicist an intent look. " Almost always," he said, with a suggestive pause at the end.

FitzHugh shook his head and gestured at the mug. "An-other, please."

"Perhaps," said Himself, "it would be better if you let it pour out instead of in."

("What"s he mean?" Danny asked. "Wisht," said Doc.) Someone put "The Reconciliation Reel" on the juke box and fitzHugh winced as the wild skirling of whistles and fiddles filled the room. Some of the old neighborhood shouted Hoo! and began to clap their hands. "You"ll think I"m a fool. Deluded."

Himself shrugged. "Does it matter if we do?"

"Sure," said Doc Mooney, "we all think that Danny here is a deluded fool; but that doesn"t stop me from buying him a beer now and then."

Danny, who could be quick on the uptake when the stakes were high, held his mug out to me and said, "You heard him."

Sure, it is not often that Doc is hoist by his own petard, but he had the good grace to accept it cheerfully. While I filled Danny"s mug, fitzHugh looked on some inner place in his soul.

"You see," fitzHugh said finally, "the brain stores memories both holographically and a.s.sociatively.

Because the memory is a hologram, one may recapture the entirety from a surviving fragment; and because they are "filed" a.s.sociatively, one recovered memory may lead to others. These shards of overwritten memories lie embedded in our minds like junk genes in our DNA, an explanation perhaps for stories of "past lives"; for false memory syndrome; or for inexplicable fugues or personality changes or...Or...." He paused again and shuddered. "Ah, G.o.d, what have I done?"

"Something," O Daugherty suggested, "that needs a hearing."

"From the likes of you?"

Himself took no offense. "From the likes of us," he agreed, "or the likes of Father McDevitt."

FitzHugh bowed his head. There had been fear in his eye, and sorrow, and despair. I wondered what odd confession we were about to hear, and ourselves with no power to bind or loose. Maura placed a hand on his arm. "Go on," she urged. Cartwright rumbled something encouraging and Danny had G.o.d"s grace to keep his mouth shut.

Finally, fitzHugh drew a shuddering breath and blew it out through pursed lips. "A man cannot be responsible for something that never happened, can he?"

Himself shrugged. "Responsibility is a rare thing in any case: a b.a.s.t.a.r.d child, often denied."

"It started with a dream," fitzHugh said.

"Such things often do. And end there, too."

"I"m not married," fitzHugh said. "I never have been. There have been women from time to time, and we get along well enough; but there was never one to settle down with. Always it was too early to wed; until it became too late."

"It"s never too late," O Daugherty said, "when the right one comes along."

FitzHugh"s smile was faint. "That"s the very problem, you see. It may be that she did, once. But..."

Melancholy closed his face again and he inhaled a long, slow breath. "I live alone in a house in the middle of the block over by Thirteenth Street. It"s a little large for my needs and the neighborhood is not the best, but the price was right and I enjoy the puttering. There is a parlor, a dining room and kitchen, plus two bedrooms, one of which I use as an office. From the kitchen, a stairway leads to a rough, unfinished bas.e.m.e.nt.

"Recently, I began to have a recurring dream. It always starts the same way. I walk through my kitchen to the back stairwell and go down, not to my own bas.e.m.e.nt, but to another house entirely, where I walk past empty bedrooms, then a kitchen with dishes piled in the sink and a greasy patina to the stove, coming at last to a parlor containing comfortable, out-of-style furniture. There are large windows on twoof the walls and, in the corner, a front door. The whole of it has such an air of dust and neglect and familiarity and long abandonment that I often find myself reduced inexplicably to tears when I awake."

"It was your subconscious," said Doc, "playing with that unfinished bas.e.m.e.nt."

FitzHugh gave a brief shake of the head. "I thought that, too; at first. Only...Well,the first few dreams, that was all. Just a silent walk through an empty house accompanied by a feeling of loss, as if I had had these disused rooms all along, but had forgotten about them. Once, I reached the front door before waking up, and stepped outside. An ordinary-looking neighborhood, but no place I"ve ever seen.

The house sat on a slight rise on a corner lot. Not much traffic. If I had to guess, I would say a residential neighborhood in a medium-big city, but somewhere off the major thoroughfares. I travel a great deal, going to conferences and such, but I have never identified that city."

He looked deeply into his ale while the rest of us waited. "The dream had a curious air to it. It felt like a memory more than a dream. Maybe it was the dirty dishes in the sink, or the out-of-date furniture in the parlor." Another quirky smile. "If a dream-world, why so drab and ordinary a one?"

I left the group to answer an urgent call at the front end of the bar, where a shortage of brew threatened several collegians with imminent dehydration. When I returned to the discussion, fitzHugh was answering some question of Doc Mooney"s.

"...so the more I thought about it and puzzled over it, the more real it grew in my mind. I remembered things I never actually saw in the dream. It seemed to me that the sink ought to have separate hot and cold water faucets. And that upstairs there would be an office and a sewing room and another bedroom. So you see, the details had the texture of memory. How could I remember those things unless they were real?"

Doc pulled the squint-eye like he always does. I think he still suspected some elaborate joke at his expense. "Imagination can be as detailed as memory. Your dream left blanks and you began to fill them in."

FitzHugh nodded. "That"s an answer I yearn for. If only I could embrace it."

"What happened next?" Himself prompted. "There must be more to it than you"ve told to account for such a melancholy."

The physicist drew a deep breath. "One evening, reading at home, I became acutely aware of the silence. Now I am a man that likes his solitude and his peace and quiet; but just for a moment the silence seemed wrong, and I wondered, What"s he up to?"

"Who?" asked Danny. "What was who up to?"

FitzHugh shook his head. "I didn"t know, then. But I glanced at the ceiling as I wondered, even though there is nothing up there but a crawls.p.a.ce and storage. And then I heard a woman"s voice."

"A woman, was it?" said Himself. "And saying what?"

"I don"t know. I couldn"t make out the words, only the tone of voice. I knew that I had been addressed, and inexplicably my heart both soared and sank. I can"t explain it any other way. It was as if I had been yearning for that voice and dreading it, all at once.

"Well," he continued, "a.s.sociative memory means that one recovered memory can lead to others; and having found a fragment of one hologram, other fragments began to surface in my mind. I had only to close my eyes and imagine the phantom house. With each return, it became more real, and the conviction grew that I had lived there at one time, and not alone. Voices-there were two of them-grew more distinct. Often angry, but not always. Once, I"m embarra.s.sed to say, whispering a s.e.xual invitation. And then, one day, I saw her."

He lifted his mug to his lips, but it hovered there without him drinking as he gazed into the dark, reflective surface. "I was puttering in the parlor, sanding down some woodwork in order to stain it. It was the sort of mechanical task that allows the mind to wander. And so mine did, until it seemed to me that I was in the kitchen of my "secret house," drying dishes with a towel. A tall, straw-haired woman was standing beside me washing them in the sink. She had the nagging near-familiarity of a once-met stranger. Perhaps I had seen her at a party in college and I never got up the nerve to walk over and introduce myself-only maybe, once, I did. I knew she was angry because she would shove the dishes into my hands in that silent-aggressive way that women sometimes use. She bore the harried look ofsomeone once very beautiful but for whom beauty had lately become a ch.o.r.e. No makeup. Hair cropped in the simplest, most "practical" style. Perhaps she blamed the me-that-was. Later, I remembered cutting remarks. She could have been this, or she could have married that. I don"t know why she kept slipping such hurts into our conversation..."He smiled ruefully. "But this first time, she turned to me and said very distinctly, "You have no ambition."

"I was so startled that I snapped out of my daydream, and there I was, back in my own parlor." He grimaced, ran a finger up and down the condensate on the outside of his gla.s.s. "Alone."

"It"s only natural," said Doc Mooney, "that a man living alone might grow wistful and imagine a married life he never had."

FitzHugh laughed without humor. "Then why imagine such an unpleasant one?"

"Because you need to feel that you made the right choice."

"You"re a psychiatrist, then, and not a pathologist?" The tones were sarcastic and Doc flushed red.

FitzHugh fell into a brown study, and fixed his eyes on the far wall. The rest of us, supposing the story had come to an unsatisfying conclusion, went about our own affairs: O Daugherty and myself to filling gla.s.ses and the others to emptying them, which division of labor made for an efficient process. Once or twice, I glanced at fitzHugh, noted his unfocused eyes, and wondered on what inner landscape he gazed.

There were tears in the rims of his eyes. When he lifted his gla.s.s to me and signalled, I gave Himself a look and he gave me the high sign, so I switched fitzHugh"s drink to a non-alcoholic beer. I don"t think the man ever noticed.

"I had a son," he told me when I handed him the freshened gla.s.s. No one spoke. Doc, from wounded pride; Danny, because of a firm headshake I gave him.

"A son, was it?" said Himself. "Sure, that"s a comfort to a man."

FitzHugh made a face. "Lenny was anything but a comfort. Sullen, secretive. Seldom home, even for meals. Lisa blamed me for that, too."

"He was a teenager, then."

FitzHugh started and a rueful smile curled his lips. "Yes. He was. Is that normal behavior for that age? For the sake of other parents, I hope not. I"ve remembered flashes of him mouthing off, and once or twice I"ve even heard echoes of the foul words he used. I"ve another memory of a policeman standing in the front door holding Lenny by the arm and lecturing me." He sighed. "Sometimes I wished we had never met, Lisa and I; and that I had married someone else and had different children; that, well...that everything had turned out better than it had."

"Then it was good fortune," I said, "that some bubble in the foam erased it."

FitzHugh was a big man; not muscular exactly, but not frail-looking, either. Yet, he gave me a desolate look and laid his head on his arms and began to weep. O Daugherty and myself traded glances and Wilson Cartwright said, "I know where he lives. I"ll drive him home." FitzHugh raised his head.

"Sometimes, I remember other things. Huddled over a kitchen table with Lisa, planning a future full of hope. A young boy bursting with laughter showing me a horse he had modeled out of clay. A camping trip in the Appalachians. Holding hands in a movie theater. Fleeting moments of simple pleasures. The joy had all leaked out, but once upon a time... Once upon a time, there had been joy."

A wretched tale, for who among us has not known friend or family in a like situation? Sure, the wine may turn to vinegar in the bottle. And yet, who can forget how sweet it once tasted?

Himself nodded as he wiped a gla.s.s clean. "Are you ready to tell us now?"

FitzHugh grunted, as if struck. His eyes darted about our little group and found me. "It was no chance bubble," he said, shaking his head sadly.

That startled me. "Then, what-?"

"I don"t know what sort of research my dream-self was doing. I recall enough tantalizing bits to realize it was down a different avenue than I"ve explored. But I do remember one especially vivid dream.

I had built a chronon projector."

Doc Mooney snorted, but Himself only nodded, as if he had expected it. Maura Lafferty wrinkled up her forehead and asked, "What"s a chronon projector?"

Frustration laced the physicist"s voice. "I"m not sure. A device to excite time quanta, I think. Into thepast, of course. There"s nothing but formlessness futureward of the bow wave. Perhaps I had some notion of sending messages to warn of tornados or disasters. I don"t know. The projector was only a prototype, capable only of emitting a single chronon to a single locus. Enough to create a ripple in the pond; not enough to encode a message." He upended his mug and drained it and set it down hard on the bar top. "Call it a "cue stick," if you wish. Something to send a billiard ball into the packed chronons of yesterday and start random ricochets of cause and effect.

"Yesterday, I had no cla.s.ses to teach, so I stayed home to paint my dining room. I was thinking about mutable time; and I had my hand raised, so." And he held his right hand just before his face.

"There must have been some congruence of my train of thought and my posture, because in that instant I was standing in a lab before some great machine and my hand was gripping a switch, and I remember...

Lisa and I had had an argument over Lenny, and I remember...I remember thinking that if I projected the chronon to the locus when Lisa and I met-to that time and place-I could create a ripple in the Dirac Sea, a disturbance in the probabilities and...It would all never have happened. None of it. The heartache, the b.i.t.c.hing, the sullen anger-" He fell silent.

Himself prompted him. "And...?"