“Prime numbers,” Evan said, his voice taking on that eager tone when he’d alighted upon a new and exciting idea. “You yourself wrote a paper on the subject.”
“Years ago,” Ó Dónaill said. “Others have since disproved the theory.”
“True. But remember the new research from Lîvod and Tlatelolco—”
“Incomplete—”
“Not incomplete.”
There was a heavy pause, and Síomón could picture the glower on Ó Dónaill’s face. It was a look that intimidated less confident students. Evan himself apparently required a few moments before he could continue.
“Begging your pardon and your indulgence, sir, but the evidence is not incomplete. Here are the newest papers, delivered just this week from a community of Iranian scholars. Have you read them, sir?”
“Not yet, Mr. De Mora. I was engaged in my own research.”
“As was I, sir. One very similar to your own, I would imagine.”
Ó Dónaill snorted. “Indeed.” But when he spoke again, his voice was oddly formal. “Mr. Madóc is your intimate friend, I believe.”
“Mr. Madóc is my dear friend and a respected colleague, sir.”
A longer silence followed, then Ó Dónaill cleared his throat. “I’m glad you paid me this visit, Mr. De Mora. Come with me, we shall go to my offices tonight. I have some papers to share—”
He broke off with an exclamation. What followed next, Síomón could not quite make out. Footsteps thudding across the wooden floor, a strange soft thump, as if a knife had been driven into a pillow, a garbled cry that robbed him of strength and sense. He doubled over, hands splayed in the cold mud outside that bright and terrible house. From afar, he heard a commotion, then a second, broken-off cry.
Síomón dragged himself upright and forced himself to look into the parlor.
It was empty, as far as he could see. Empty and bright and silent.
Without thinking, he raced to the front porch and flung the door open. A silent foyer met his eye. Cautiously he stepped inside, his heart beating hard against his chest. He heard a rustling from within the parlor and laid a hand on the latch.
The metal stuck at first. He pressed harder. The latch gave way with a loud click, and the door swung open. For a moment, he could not comprehend what he saw. A branch of candles on the mantel. The hearth itself giving off a glow from its banked fire. Several chairs overturned. And then, he saw what had not been visible from the window itself—two dark shapes lying motionless upon the carpet, one with fine white hair, one with blond, bleached to silver in the lamplight.
Evan. Ó Dónaill. But that means—
He heard a scrabbling. Before he could register what that signified, a man burst from behind the couch and ran full tilt into Síomón. They both tumbled to the floor, arms and legs flailing as they wrestled. Síomón found himself pinned on his back, the stranger gripping his throat. Síomón dug his fingers into the stranger’s wrist, broke free, and rolled to his feet. The next moment the stranger had done the same.
He was a tall man, with pale blond hair escaping from underneath a knitted cap, and his light blue eyes glittered in the moonlight. He could almost be Evan’s brother. In his left hand, he held a butcher’s knife, the point angled upward. Blood stained the blade.
Síomón’s stomach lurched. He stumbled forward, hardly knowing what he did. To his surprise, the stranger gave a muffled cry and ran.
“Stop!” Síomón cried.
“Stop!” cried another voice.
Ó Deághaidh. In relief, he swung around. “Commander. Thank the Lord and Lady—”
Ó Deághaidh stepped over the threshold, his gun aimed at Síomón’s chest. “Síomón Madóc, I order you to yield. Give me the knife, sir. I promise that it will go better if you cooperate. Come, lay the knife down. You know you have not a chance.”
Síomón edged away. “What are you talking about? Didn’t you see the man? He’s the one who killed—”
With a shock, he realized he gripped a knife in his left hand.
He flung the knife away in horror. It clattered to the floor and bounced toward Ó Deághaidh, who dropped to one knee and fired. Síomón twisted away, but not in time. Pain blossomed in his shoulder. In panic, he stumbled down the hall and made it through the back door a few steps ahead of Ó Deághaidh.
A garda loomed to his right. Síomón swung a punch and connected. The pain in his shoulder nearly brought him to his knees. Ahead, he saw another figure darting through the gate and into the alley. Síomón drew a sobbing breath and ran.
* * *
Dawn came as a dark red haze.
Síomón pressed his hands against his eyes, trying to contain the pressure inside. He’d spent half the night chasing and being chased. Twice he had spotted the murderer, and twice Ó Deághaidh’s men had nearly captured Síomón. Finally he’d taken refuge in a derelict stable, deep in Awveline’s slums.
He tilted his head back and breathed in the dusty air. His shoulder ached fiercely where Ó Deághaidh had shot him, and dried blood pulled at his skin. It would be only a matter of hours before Ó Deághaidh and his patrols located Síomón. They would charge him with murder, try him, and execute him. And why not? The proof lay at his feet—the bloody knife that killed Evan and the professor—even though he clearly remembered dropping it inside Ó Dónaill’s house. He also remembered a stranger fleeing with the same knife in his hand. Two memories, equally vivid. Which one was true?
“Seven,” he whispered. “Thirteen. Seventeen.” He paused and listened a moment. A pattering against the doors and broken shutters told him that rain was falling. A faint silver light seeped around the shutters. Day had arrived.
“Nineteen. Twenty-nine. Thirty-one—Fuck! Damnable fucking numbers!”
A coughing fit overtook him. Síomón fumbled in his jacket pocket for his handkerchief. His fingers met a square packet.
“No,” he whispered. “That’s not possible.”
Síomón pulled out the packet and ripped off one corner. He poured the contents into his hand. After a moment’s hesitation, he tipped back his head and poured the cocaine into his mouth.
A bittersweet taste filled his mouth. His stomach heaved in protest. Choking, he managed to force the powder down his throat.
His tongue went numb. Next came the tremors, which shook him so hard that his fist knocked against his teeth, and he tasted blood. His chest felt tight, as though a vise gripped him. Hard to breathe, hard to—
* * *
I had trouble finding you.
Midnight in the orchard. A bright half-moon illuminated the trees with clouds of light. Síomón held Gwen tight against his chest to quiet her trembling. Her hair smelled of new apple blossoms. Underneath, however, lay the distinct scent of fear.
What is wrong, Gwen? What happened?
I can’t sleep, thinking about numbers. Remember what Pythagoras said, about numbers and the soul. What the mystics said about the paths our lives take.
One memory blurred into the next. Memories of comforting Gwen after her nightmares. Memories of rigorous arguments, where each delivered their reasoning in dispassionate tones. Memories of a life shared so completely that Síomón often wondered if their separate bodies were just an illusion.
Look, Síomón.
* * *
Images of the moonlit orchard overlaid those of the stable. Even as he watched, the silver-dappled leaves faded into stone, and the moonlight dulled to a rain-soaked dawn.
The murderer crouched opposite Síomón. His long hair hung in wet tangles over his face. Síomón scrambled to his feet and snatched up the knife. The man did not acknowledge him at all as he poured out a quantity of white powder onto his palm.
Breathless, Síomón watched him swallow the cocaine. The stranger wore his face, with all the differences age would make. Silver threaded the fair golden hair. Lines radiated from his eyes and mouth. The flesh along his jaw drooped slightly. A handsome man just entering middle age.
/> Síomón laid a hand over his own shirt and felt the cocaine packet in his breast pocket. No longer surprised, he too took out the packet, poured out the entire contents, and swallowed them. When the stranger rose and walked out the door, so did he.
Outside, the slums had vanished into a haze. Síomón and his twin walked along a strange path lined with dense green foliage. Above, stars burned like digits of a never-ending number.
They came to an intersection, where a dozen paths curved toward the horizon. Impossible, Síomón thought. The Earth curved, certainly, but the unaided eye could not discern it. He glanced toward one of the branches.
They were nineteen. The hazy sunlight, falling through the leaves, cast green shadows upon Gwen’s face, which had the luminescence of youth.
“The past is not immutable,” she said.
“How?” Síomón demanded. “You’ve not proved your theories.”
“I don’t have to. We prove it by living. Our parents proved it by dying.”
They stood by the sunken gardens, underneath a stand of ornamental trees. The late summer sun glittered upon the pool, and a brilliant haze filled the air, making the trees and foliage beyond appear indistinct. Síomón blinked to clear his vision. Paused. Gwen had gone silent, and he sensed a difference in the air. When he glanced back to his sister, he saw creases beside her eyes and strands of silver in her hair.
Thirty-seven.
David Levi bent over a workbench, delicately twining copper wires onto a perforated board. Maeve stood by a tall desk, writing out columns of numbers.…
Forty-one.
The same room, but a different day. He and Gwen stood over a worktable, which was hidden beneath an enormous sheet of paper. Lines covered the paper in a complex grid of red and black and blue. Green circles marked certain intersections; their distribution made a pattern that Síomón could not quite grasp.
Gwen was speaking in low urgent tones. “I thought Paul could manage. He and I discussed it. I judged the risk acceptable.”
“You’re letting emotion distort your judgment.”
“Not this time,” Gwen insisted. “Look. Forget the ordinary intersections. We’ve already identified the ones that matter. Here—” Her finger hovered above one of the green circles. “And here. And here.”
Seven. Thirteen. Seventeen. Nineteen. Twenty-nine …
“I know that,” Síomón said. “But we have not identified all the permutations of twenty-three. Until we do, the path remains incomplete, and we cannot risk making even one journey.”
“141955329,” Gwen said crisply. “Times two. Exponent 25267. Add one. Ó Dónaill confirmed the latest pair of primes yesterday. He said that true pioneers cannot always wait for absolute knowledge before testing their theories. You used to believe that yourself.”
“In a different time line,” Síomón said. “A safer one.”
“This one is safe.” She jabbed her finger at the intersection marked twenty-three. “David ran the new primes using the same formulae. The results looked promising. Take the route through this intersection, and we have a clear path to the day in question. Alter one conversation—just one—and that balloonist might have known about the high winds. He might have—” She stopped, drew a deep breath. “He would have chosen a different route and avoided the accident. Our parents would have lived.”
“What about the permutations?” Síomón asked softly.
Gwen set her mouth into a thin line. “Close enough.”
“Obviously not.”
Tears brightened her eyes. “Obviously not. Síomón, we were so close, and when Paul volunteered…”
It was Paul Keller who first had the idea of using prime numbers in their work. Li Cheng and Úna Toíbín had researched the formulae they needed, and David Levi had designed and built calculators to speed their computations. Nicolás Ó Cionnaith had alighted upon the inspiration of linking the human brain with the machine. From there, Evan, Maeve, and Ó Dónaill had begun to map out a viable path through the past. But it was Gwen who deduced they could use a combination of numbers and drugs and electricity, just as the old mathematician-conjurors had claimed.
“We can start with cocaine,” she told the others. “And test its effects on varying levels of current.”
The results had proved terrifying. And effective.
We used our madness and our genius, Susanna used to say, and from that we would benefit mankind.
Síomón took his sister into his arms. “Hush, Gwen. We’ll get Paul back and try again—after we check the numbers more thoroughly.”
She made an involuntary noise. Warned, Síomón took a step backward and studied his sister’s expression. “What? What else happened? Tell me.”
Gwen opened and closed her mouth. “Time fractures,” she said with obvious difficulty.
Síomón drew a sharp breath. He’d read about the theories and discounted them. And yet, the concept of time fractures was no more fantastical than his and Gwen’s own theory that said time lines followed the curvature of space, bending gradually over vast distances and meeting themselves again at different points.
“I’ll have to go back myself,” he said.
Gwen’s mouth tensed. She was speaking again, but Síomón could not make out the words. Something about patterns overlaying other patterns and creating chaos in the time streams.
“Too late.” Gwen’s voice was a disembodied whisper. “We were too late to save them.”
“How do you know?” Síomón asked.
Of their collaboration, only he, Gwen, Ó Dónaill, and Evan De Mora remained. Nicolás Ó Cionnaith had followed Paul Keller through the time lines, never to return. Lost, Síomón told himself. Reluctantly, he’d allowed Úna Toíbín and Li Cheng to launch an expedition to recover their colleagues, but, instead, they were the next to vanish—their existence blotted out when two time lines reconverged. At that, Síomón ordered the equipment locked up, and the experiment shut down. To his dismay, Maeve defied those orders, convinced she had the key to their problems. When Susanna, mad with grief, chased after her friend to prevent another death, she too died. Time had fractured, and the paths no longer ran true.
“We cannot do nothing,” he said to Gwen. “I must go—”
“But Síomón—”
“I’ll take the same path as Paul,” he said, speaking over her. “I’ll find him and do whatever is needed to remove the fracture.”
Gwen pressed her hands against her cheeks. She made no objections, however, and when Síomón indicated for her to assist him in preparing their apparatus, she did so, albeit silently.
One moment of inspiration, Síomón thought, as he tapped the keys rapidly. Decades of necessary research and experimentation had followed, but it was that initial insight that counted most. Strange to think that that same moment intersected so many other time lines. It had taken the best minds in Éire’s universities to invent the necessary formulae for traversing those lines, and more complicated formulae with ever higher primes to calculate all the factors involved in shifting those lines to alter the past.
Gwen injected the cocaine and counted until the drug penetrated his bloodstream. Síomón waited until she gave the signal before he pressed the last digit and set the last control. His gaze met Gwen’s. She managed a smile, however unconvincing. Then Síomón pressed the switch to connect the electrical current.
Darkness. The scent of raw earth and pine needles crushed underfoot. He walked by instinct, having made a brief essay with the machine before, when they had first tested its capabilities. Even so, he found the lack of physical indicators unsettling. The vivid scents, the cold prickling his face, the pinpoint stars, were all trace memories, Professor Ó Dónaill claimed. Perhaps that accounted for the sensation of being doubled, as though another presence existed within his mind.
It did. It will. It does.
He paused and looked back the way he had come. A short distance behind him, the path split in two, each branch leading to a different fu
ture. With a chill, Síomón could make out threadlike strands beside each branch, signaling further confusion in time.
I’m not too late, he told himself. If he intercepted Paul before the crisis, time would heal itself, or so Gwen had insisted. Even now, the worst would be a blurring of the past. Events doubled. Contradictory memories. Nothing fatal.
His pulse beat an irregular rhythm. Down each strand of time, another of his selves existed. He was doubled and tripled, each self bound to the other through a tenuous connection. When he glanced back, he could swear the strands grew more numerous. Was time unraveling toward the future and Gwen?
He hurried on. With every step, the air turned thicker, pressing against his lungs. Voices whispered in the paths beside his. No, it was a single voice, speaking different words, depending on which direction Síomón tilted his head.
Time fractures.
He could reenter time at the next intersection. Ó Dónaill’s calculations predicted a narrow crack, corresponding to the prime number pair. Twin primes, he called them.
But Ó Dónaill had stolen his theories. Borrowed them for his own research, he called it. Or had he simply refined the formulae and shared them with Síomón and Gwen? Síomón found it harder to remember which version was true. The voices distracted him, and the pressure had grown almost unbearable, drilling into his temples.
Panicked, he stumbled forward. He heard a roaring ahead, a cataract of time, spilling through the cracks into the world. If only he could reach it before he died from the agony. That was how Úna had died. And Paul. And …
He fell through the tunnel’s diaphanous walls into a muddy clearing. A cold wind swept through his clothes. His hands stung from the fall. Strange noises and images assailed him. Raucous cries echoing overhead. Misshapen shadows blotting out the sun. Then, in the midst of strangeness, a human voice.
The Time Roads Page 11