Click. The second handcuff is applied. Jonas grits his teeth, continuing to strain. He’s losing feeling in the fingers of both hands as they writhe against each other like two fighting squid. Above him, the cop shifts his weight, readying himself to haul Jonas to his feet, but then Jonas’s fingers seize on the tether—a good grip, finally—and pull it from his finger, clutching it tight in his other hand.

Jonas doesn’t know what the cop will think of what happens next. He has no idea how the officer will explain it to himself or his superiors. Surely, he will interrogate the gathering crowd and implore, “Did you see that? Did you see that?” But Jonas doesn’t care. The now-familiar tingling sensation courses through him once again. Light blazes. Space folds. The handcuffs, some cash, a freshly minted United States passport, and an American Express card fall to the sidewalk, and Jonas blinks from the world.

Maybe it’s the fact that Jonas is lying on the ground. Maybe it’s that his heart is now broken beyond repair. Maybe it’s that his body is still processing the quantum radiation with which he’s flooded his cells. Whatever the explanation, the experience of reality-slipping feels different from before. This time, he feels a miasma of physical pain, a thin coating of agony over pins and needles in his extremities.

The concrete sinks beneath his body, as though the sidewalk is absorbing him. But that’s not it, he realizes. The concrete has been replaced by a thick carpet of grass. The blades tickle his face. The scent of pine fills the air. Jonas staggers to his feet and sees that the entire city is gone, its concrete canyons replaced by undulating fields of grass as far as he can see. It’s beautiful. The sky is a violent crimson, a red deeper than any dawn or sunset.

He’s slammed down again. The city has returned, along with its omnipresent pavement. The fall exacerbates the concussion Jonas is sure he’s received, and he’s assaulted again by another volley of what knocked him over in the first place: water. Torrents of it charge past him, the city’s buildings acting like massive sluice gates. The rush rag-dolls him again, the water sending him hurling toward a towering office building. A wall of steel and glass rises to meet him, and once again, Jonas thinks this is the end.

But a reality-slip swaps the building for only slightly more forgiving ground. He lands hard. Once again, New York’s concrete proves a harsh mistress. He fights disorientation as universes cycle past. Each reality-slip is the pull of a trigger in a cosmic game of Russian roulette, and it’s a daisy chain of good fortune that he hasn’t been worse than injured thus far. He has won a few seconds of calm and spends them on returning the tether to his finger. The cascade of alternate realities slows, and Jonas looks down at his hand, where the tether’s white pulse is as soothing as a mother’s touch.

He breathes deep and is rewarded with the smell of shit. The air is also thick with the smell of burnt rubber and electricity. The ground is hard beneath him. Gravel digs into his buttocks. A newspaper wafts past. He sees other refuse—a bottle, a purse, a boot—scattered about him in the darkness. One piece of trash is an empty coffee cup. He has traveled through multiple realities, entirely different universes, to find the Starbucks logo staring back at him.

A rat skitters past, causing Jonas to startle. Wherever he is, it’s not the kind of place he wants to stay for long. But he’s so broken, in both body and spirit, that he can’t summon the energy or the will to stand, much less walk. The blood in his head mounts a fresh assault with every heartbeat. A pain in his side punishes him with every breath. So even though it’s dark, even though he’s surrounded by trash and vermin and the smell of burning rubberized shit, he doesn’t even consider moving. The hard ground and harder wall that presses into his back, cold and unyielding, feel like the downiest comfort he’s ever experienced.

As his breathing slows and his pulse descends to a manageable gallop, the twin assassins of loss and hopelessness steal their way back into his thoughts. Emotion bubbles up from his depths. Grief clutches him and squeezes. His eyes begin to well with tears.

And that’s when he hears the screaming.

No, that’s not right. It isn’t a human scream but a marriage of high and low pitches, part whistling and part thrumming. And growing closer.

The ground beneath him tremors. The gravel does a little dance. He sees three ribbons of steel transecting the ground. A subtle light bleeds in, revealing to Jonas where he is.

He’s in a tunnel. And judging from the encroaching light and the approaching “scream,” it’s a subway tunnel.

He shoots to his feet. Grief steps aside so that fear can have a turn with him. He spins away from the approaching light and sees nothing but a long stretch of darkness in front of him. The rumble announcing the subway train’s approach feels like an earthquake.

Jonas is now enticed by the thought of death. He has felt this temptation before, the desire to surrender everything, to escape the grief and despair and pain, to sleep at last. The advancing subway train offers an end to the horrible Amanda-less existence he’s endured for over two years now.

Without thinking, he steps into the center of the tunnel, casting himself in the subway train’s oncoming light. It will be upon him in minutes, if not seconds. If he closes his eyes, he won’t see its arrival. He’ll feel nothing, except maybe the heat of the train’s approach, and then it will all be over.

But the human will to live is perhaps the strongest impulse in creation, the drive that makes all other drives possible. And so when Jonas sees the outline of a steel door to his left, illuminated by the growing light from the advancing train, he recognizes it for what it is: a way out. A way to live. He bolts toward it as the tunnel gets brighter. He grips the handle, but it fights him.

The earthquake grows more forceful.

Jonas calculates that he has mere seconds until he’s smeared against the very door he’s trying to open.

The handle gives way with a crunch of rust, but more rust at the base of the door prevents Jonas from opening it farther than half an inch.

The tunnel grows brighter.

The train is almost on top of him.

With increasing urgency, he throws himself against the door, hammering it with his shoulder again and again and again. But apart from that initial half inch, the door remains as immoveable as a rampart.

The metallic wail that heralds the train’s arrival is almost deafening now.

Jonas takes a few steps back from the door. He can see the train now. Two halogen lights scream toward him. Behind a wall of black glass, the driver reacts with panic and horror at the sight of him.

Then, a squeal erupts like the plaintive cry of a wounded animal, but it’s the application of brakes on a doomed mission to slow an 85,200-pound steel missile going fifty-five miles per hour.

Jonas hurls himself at the recalcitrant door again. His head pushes past his shoulder and strikes the metal with a sickening thud. He is falling again, not down but forward. As he hits the concrete floor, a wall of hot wind pushed by the passing of the train floods over him. Whatever space he’s entered trembles in its wake.

He doesn’t bother to stand. He lacks the strength. He’s at the base of a flight of metal stairs. The rest of the room is concrete. On one wall, there is signage marked with a cobalt blue logo, a circle with the letters MTA overlapped in white. Metropolitan Transit Authority.

The stairs loom before him. An invitation. But with safety comes the return of dolor, of desolation. The feeling of loss returns to overwhelm him, and he gets back to the business that was at hand before the subway interrupted him.

He cries.

But these tears aren’t the same as the ones that gently fell from his eyes as he was holding Amanda for the final time, watching her breathe her last. Jonas cries with a violent urgency, forcibly expelling the tears from his body. Lying on the cold concrete, he wails. Each heave of his chest, each feral scream extracts a new volley of tears, like squeezing out water from a sponge. No one descends the stairs to intrude. Jonas is free to weep and howl and undulate on the floor for what feels to him like hours.

When he’s finished, all he wants to do is sleep. He’s never felt more tired but still wills himself to his feet. He recalls the time between Amanda’s death and the realization that his work might provide a way of reuniting with her. In that interval, the intermediate stage between desolation and hope, Jonas learned that sometimes the hardest thing to do in life was just to live. It seemed impossible then. It feels impossible now. But having ruled out suicide, he has no other choice.

He shuffles to the stairs and begins to climb.

FIVE YEARS AGO

Jonas was lecturing to his class about quantum entanglement when it happened. “Philosophy tells us that two contradictory things cannot be true at the same time. Physics tells us that two different objects cannot occupy the same space at the same time. Quantum physics, though, contends the philosophers and the physics experts are wrong.”

The lecture center was arranged like an amphitheater, with Jonas standing at the bottom, flanked by a flock of whiteboards and looking up at a sea of open laptops and an assortment of expressions that ranged from studiously interested to bordering on somnambulant. The room was three-quarters filled, seventy-five or so students—just enough to provide a crowd whose energy he could ride like a surfer cruising a wave. It was an energy exchange he’d come to understand over his years of teaching. He found the attentive listeners in the throng and gave his energy to them, which they would return, energizing him further. It was a flywheel, a virtuous cycle. And he would have been lying if he said he didn’t love it.

“What we’re talking about here is the phenomenon that occurs when two or more particles share a given space in such a way that the quantum state of each particle cannot be measured independently of the state of its peers. The two or more particles are said to be, at that point, ‘entangled.’” Jonas’s hands were flying, drawing the arc and relation of invisible particles in the space in front of him. “In fact, entanglement is the primary difference between classical physics and quantum physics. It’s a keystone idea, an idea which makes subsequent ideas possible. One of those ideas is that of quantum computing. Traditional computers are built on a binary architecture, ones and zeros. Each literal bit of data is either one or zero.”

He had digressed—drifted out of his pedagogical lane—but he was on a roll, carried along by the momentum of his thoughts. Despite his detour, the energy exchange with his class remained potent. Even those who had been texting or daydreaming appeared focused. “But quantum entanglement recognizes a third possibility, that of the one and zero coexisting, being both true and false”—he paused for effect—“at the same time.”

He crested so single mindedly on the wave of his rhetoric that he didn’t even hear the snare drum roll. It wasn’t until he heard Frank Sinatra’s voice—Why do I do just as you say?—that he saw Amanda walking down the lecture hall’s steps to meet him. It was fall, and she wore her hair down, her locks falling over a green cashmere sweater. She had a puckish glint in her eye and a Bluetooth speaker in her hand. “It Had to Be You” poured out of it.

The students smirked and tittered. Some flashed scattered looks of confusion, but they were in the minority. Amanda stood on the stairs that bisected the lecture hall, her hips swaying, as she lent her voice to Sinatra’s.

Why must I just give you your way?

Jonas grimaced. “It seems my girlfriend is trying to make a point.”

Then, to his surprise, a few of the students joined in. Their accompaniment felt more planned than spontaneous.

Why do I sigh, why don’t I try to forget? It must have been that something lovers call fate.

“And”—he drew out the word, smiling through his teeth—“she’s apparently drawn a few of you in as coconspirators.”

As it turned out, it was more than a few. Soon, the entire class was singing along loud enough to drown out not only Amanda but the Chairman of the Board as well.

Kept me saying I have to wait, I saw them all, just couldn’t fall, till we met.

Amanda raised her voice above the students and the speaker, her hair swaying as she bobbed and weaved in time with the melody.

It had to be you. It had to be you. I wandered around and I finally found the somebody who could make me be true . . .