“Step away,” Jonas admonishes him. “I’ve released the safeties on the machinery. Do you understand? If you stay here, I can’t guarantee your safety.”

“Descends par terre,” the soldier repeats.

“I’m really very sorry,” Jonas says with sincerity. All around him, miles of machinery grow louder, building to a thundering crescendo.

It’s time.

Jonas closes his eyes.

And waits.

And waits.

Nothing happens.

Impossibly, incredibly, nothing happens.

Jonas opens his eyes.

He barely has time to ask himself what he could have gotten wrong, which calculation was off, which variable unaccounted for, when the soldier is on top of him. Jonas opens his mouth to speak—and say what, he has no idea—when the butt of the man’s rifle hits him square in the face.

The world goes black.

FIVE YEARS AGO

Perfect sunshine beamed down through the trees, their branches drawing little spangles of light in the air and casting shadows on the South Lawns. The skyline of Manhattan raked the perfect blue overhead, surrounding it like the fingers of a giant who nestled the campus of Columbia University in its massive palm. Faculty laced the lawn, shuttling to classes or back to their offices. Graduate and undergraduate students ran and walked and flirted, while others leaned against trees or sat at outdoor tables. The air smelled of spring, a cocktail of jacarandas in bloom and winter in retreat.

Finished with his classes for the day, Jonas walked with his fellow professor, Victor Kovacevic. Victor was more than a mere colleague. Jonas would have described him as a friend. Victor, six years older, would have described himself as Jonas’s mentor. Both were accurate.

At six feet, four inches, Victor’s frame was gangly, and his clothes—on this day, a pair of jeans and a dress shirt with the sleeves rolled up—had a tendency to drape off him like cobwebs. He wore a thin goatee, which Jonas suspected was dyed, despite the fact that Victor was only in his early forties. He wore glasses with Transitions lenses that were dark gray in the sun.

As they traversed the campus back to their faculty offices, Jonas handed Victor a sheaf of papers covered in a mélange of equations and formulae, written in a mosaic of mostly pencil and blue and black ink. Red marks made the occasional appearance, dotting the pages like a teacher’s corrections on an exam.

“Would you take a look at this for me?” Jonas asked. “I’m curious to know what you think.”

Victor grimaced at the untidy stack. Jonas was the only faculty member he knew who still worked longhand instead of on computer or tablet. Victor acted as if he found the practice to be an amusing eccentricity, but Jonas had never been sure. Despite knowing the man for over ten years, Victor Kovacevic remained to Jonas an inscrutable, sphinxlike figure. To the extent that Victor exuded any emotional qualities, they had the tendency to be limited to amusement and vexation, though it was often hard for Jonas, or anyone else, to distinguish between the two.

“What’s this?” Victor asked as he leafed through the pages. But the question itself was mendacious. A physicist of Victor’s brilliance could decipher Jonas’s calculations at a glance.

“It’s early stages, but I think I’m close to a methodology for solving the problem of quantum decoherence . . .”

“Drifting a little out of your lane, aren’t you?” In the arena of passive-aggressive put-downs, Victor Kovacevic had no equal. In this instance, though, he wasn’t entirely wrong. While physics was Jonas’s discipline, he had rarely ventured into the realms of theoretical or quantum physics that were Victor’s domain.

“I happened to enjoy a flash of inspiration.” Jonas shrugged with as much humility as he could muster, a hedge against Victor’s ever-fragile ego. “Maybe it’s something, maybe nothing. Probably nothing. But I remember how you said your ‘many worlds’ proof broke down over quantum decoherence and—”

Victor cut him off. “And you thought you’d apply salt to the wound?” he asked, flashing a taste of the anger that had cowed countless students, teaching assistants, and the occasional faculty member over the years.

“I thought I’d help.”

Victor had tried for years to develop a means of proving the existence of multiple universes, or parallel realities. He had worked with intense focus and brilliant creativity, the perfect combination of inspiration and perspiration that Thomas Edison had famously spoken of. Jonas was convinced that Victor was working his way to a Nobel Prize, although even that achievement would be too small to encapsulate the magnitude of an actual mathematical proof of the existence of parallel worlds.

But one day, as quick as a thundercrack and for reasons Jonas could barely grasp, Victor declared the project a failure. In a fit of characteristic pique, he destroyed all his notes and research. An attempt at glimpsing a vast multitude of realities ended in scorched earth.

“I stopped working on this three years ago,” he reminded Jonas.

“I know—”

“After fourteen years.” Victor’s voice was cold, clipped. Jonas watched as his jaw tightened and the muscles in his neck tensed.

“I know—”

“Fourteen years, and you think you’ve got it solved in—what was it?—a ‘flash of inspiration’?” Victor made no effort to hide his skepticism and let disdain drip from every syllable, waving Jonas’s papers around as though to cast them into the wind.

“Victor—” Jonas started, trying to adopt a diplomatic tone.

“Inspiration, I suppose, that eluded me,” Victor interjected, his tone indicting.

“I was just trying to help a friend,” Jonas said, laboring to keep even a hint of defensiveness from his voice. “I thought, if you see something of value in here, maybe we could collaborate.” He indicated his work, which Victor was still clutching.

“So I’m a charity case now, is that it?” Victor’s voice was like ice.

Jonas shot Victor a chiding look. “C’mon, man, don’t give me that.” He pointed again to his notes. “This is just a fresh perspective from a colleague.”

“And I appreciate it,” Victor replied, but his words lacked sincerity, the performance of an actor reading a line from a script he found inauthentic. Then, he softened. “I wasted more than a decade on parallel-worlds theory,” he said, making no effort to hide the pain of that endeavor. “Don’t make my mistake.” He whipped the sheaf of papers back into Jonas’s hand and continued on with neither a goodbye nor an apology.

Jonas watched him recede into a sea of coeds and administrative buildings. He looked down to consider his work and tried to reevaluate it in light of Victor’s ill-fated project. Was it hubris to think he might have succeeded where Victor had failed? Quantum physics wasn’t in Jonas’s wheelhouse, as Victor had been only too quick to point out. The truth, though, was that Jonas really felt like he was making progress. Quantum decoherence—the loss of a definite phase relation between a quantum state and its environment—led to a wave function collapse, among other things. Studying his calculations, Jonas once again felt a swell of excitement, like a hunter who has caught the scent of his prey. The work wasn’t finished, not even close, but Jonas could see the path forward. His mind imagined a set of gears and tumblers, a visualization of all the problems still left to solve, but he could see the beginning of a way that the gears might mesh, the tumblers fall into place, a virtuous cascade of breakthroughs that could, one day, open the lock that had so vexed his friend.

Then the papers scattered, and he felt a dull pain in his hands. As the sheets swayed in the wind, dispersing like a flock of birds, a fluorescent object fell at Jonas’s feet. A Frisbee.

“Ohmygod!” came a female voice. The voice’s owner quickly followed and immediately set to work collecting the wayward papers. “I’m so sorry!”

Jonas stared at the woman, in her early thirties from the look of her, and he felt his life change. She wore flip-flops and shorts and a pale-blue T-shirt with the name of some band Jonas had never heard of (Ash Dispersal Pattern). Her brown hair was pulled back in a high ponytail, exposing her blue-gray eyes. Jonas saw a small tattoo on her inner right wrist: an Ouroboros, a snake eating its own tail, curled into a sideways figure eight, the symbol for infinity.

“I’m horrendous,” she said as she retrieved the last sheet and returned the reconstituted stack to him. “I hope I didn’t ruin anything.”

Jonas was suddenly conscious of the gaping silence between them. He was at ease when talking to women, but flirting was an art as elusive to him as playing the piano. “It’s fine. Thanks.” He instantly chided himself. He had three PhDs, and that was the best he could do? One word per doctorate? Pathetic.

The Frisbee caught his eye. It rested on the grass and practically shined with potential. He stooped to pick it up and, returning it, managed to say, “I’m Jonas.” Five words. He was on a roll.

“Amanda.” She waved her chin toward his papers. “I’m sorry about mixing up your math papers there . . .”

“It’s quantum physics,” Jonas replied, instantly wishing he could reel the words—so stupid!—back in.

But for some reason—by some miracle—Amanda seemed to find Jonas’s unease charming. She flashed a smile that illuminated his entire world. He could spend the rest of his life basking in the warmth of that smile.

“Again, sorry.” She waved and began to move off.

Jonas watched her retreat. His brilliant mind was screaming at him not to let her get away. “What’s your field?” he managed to croak, desperate to say something, anything at all. Three more words, none of them particularly interesting or original, but at least he managed to keep the desperation from his voice, he hoped.