“I’m afraid you’ve lost me,” Eva admits.

“Think of a beach,” Thibault says. “With an uncountable number of grains of sand, rocks, pebbles, seashells. To catalog it all would be impossible. But Jonas has figured out a way to calculate, to predict, how many grains of sand, how many rocks, et cetera.”

Eva grasps the point. “And he’s looking for the grains of sand where his wife is still alive.”

“That’s correct.” Thibault stands with a resignation that fills Jonas with creeping dread. The affect of an oncologist armed with a damning MRI scan. “But I think you already know what I’m going to tell you.”

Jonas does. “The reason,” he says, “that I’m having such difficulty calculating the reality where Amanda survives the accident . . .” His voice trails off. The act of giving voice to his lack of hope fatigues him beyond his capacity to speak.

Thibault picks up the train of Jonas’s thought. “Out of a nearly infinite number of probabilities, there’s only one where your wife is still alive.”

If hope were a living thing, this is a death sentence. One that Jonas had rendered weeks ago but lacked the courage to face.

Eva shakes her head, confused. “Wait. Just wait.” The two men watch her think, wrapping her brain around the impossible. “You’re saying that out of the entire multiverse, Amanda dies in every single one.”

Thibault is the first to answer. “I’m saying, Dr. Stamper, that while there may very well be an infinite number of worlds, they all tend toward the same qualities. They all have gravity, for example. Oxygen. People. The multiverse is replete with these tendencies, these ‘laws,’ for lack of a better term. In the case of objects, we call them ‘physics.’ But in the case of people, we call them . . .”

“Fate,” Eva breathes, her tone full of epiphany.

“Fate,” Jonas echoes. “Or destiny.” Fate and destiny aren’t phenomena that scientists care to traffic in, any more than faith and religion, but he’s found them to be as real as time, as immutable as gravity. “It’s Amanda’s destiny to die in that accident,” he finally acknowledges. The words catch in his throat. In his mind’s eye, he watches his wife die for the millionth time.

“I’m very sorry,” Thibault says.

“You said . . .” Jonas lurches, his mind flailing. His thoughts are plummeting, thrashing about, desperate for any handhold. “You said that according to my calculations, there is a reality where Amanda is alive. ‘One reality,’ you said.” His eyes plead with Thibault for this to be true.

The older professor’s head bobs slowly, almost imperceptibly. Jonas can see the man’s prodigious brain working. Game, as his students used to say, recognizes game. “Through my university,” Thibault says, “I have access to a supercomputer that should aid considerably in making the calculations required to pinpoint it under your rubric.”

It’s all Jonas can do not to drop to his knees in gratitude. “You would do that for me?”

“Publishing wouldn’t be without its challenges,” Thibault muses, indulging in massive understatement. He winks like a coconspirator. “But I’ve been craving another Nobel.” He hefts the laptop with some reverence. “All kidding aside, the work you’ve done here, Dr. Cullen, is beyond what even a room full of Nobels could acknowledge.”

Terms are negotiated. Thibault will need a week at least. He’s free to publish whatever he wants, wherever he wants, and to use Jonas’s name and all his calculations. But even as Thibault negotiates, Jonas’s mind is somewhere else. He feels an emotion so alien to him he didn’t even feel it at CERN. For the first time in two years, he feels hope.

Night falls, and Jonas remains ebullient as Eva drives her secondhand FIAT down the Seidenstrasse, a modest two-lane highway. She doesn’t speak. After nearly a half hour on the road, the silence has grown loud.

“Penny for your thoughts?” he ventures. “Do they have that idiom in your universe?” Maybe he can lighten the mood with humor.

“I don’t really want to talk about it,” she says.

Jonas doubts anyone has ever said that and meant it. “Are you okay?” he asks.

“I said I don’t feel like talking.” The lights of a nearby city comet past.

“I know. You seem upset about something.”

“That’s one way to put it.”

“Or you could put it another way,” he tries. “You could talk about whatever it is that’s bothering you.”

“Right,” she says with a hint of sarcasm, “because when I said that I didn’t feel like talking, what I really meant was that I wanted to talk.”

“You’re right. I’m sorry to push.”

They drive on. In the quiet of the car, each little sound seems magnified. The tires bumping over the seams in the highway. The purring of the engine. The snapping of Jonas’s knuckles as he cracks them in a vain effort to fight his discomfort.

Finally, Eva breaches the silence. “You made it sound,” she begins, her tone clipped, “like you were doing something noble—even heroic—just trying to get back to your wife.”

Jonas is confused. “I am,” he reassures her. “That’s all I’m trying to do.”

“Thibault said the universe favors certain outcomes.” She says it like an accusation.

“Actually, I said it. I told you that weeks ago, and Thibault merely confirmed it.” He shakes his head, at a loss. “What’s going on?”

Eva’s hands grip the steering wheel tight. “You told Thibault . . . back at the university, you said that your wife . . . I’m sorry to put it so bluntly, but you said it’s your wife’s fate to die in that accident.” Jonas watches her frown in disapproval. But not at him. At herself. He can see she doesn’t want to be this person.

“That’s right. And so?”

“So,” she says, biting off each word, “you’re screwing around with the fundamental laws of the universe.”

“Actually, I’m screwing around with the fundamental laws of the multiverse.” Another attempt at lightening the mood.

It doesn’t work. “Don’t make light of this,” she snarls. Then, calmer, “My Introduction to Physics professor liked to say, ‘Einstein described the workings of the universe as being like a finely tuned watch.’”

“Yes. Einstein said that. I’m sorry, but what’s your point?”

“That watches are fragile.” Eva takes a deep breath. Her exhale is ragged. Primal. She takes her eyes off the road to drill them into his. “You think you’re the only person to have lost something or someone? The only person who wishes things were different? That the dice roll of their lives came up as another number?” She doesn’t raise her voice, but it trembles with rage. She returns her eyes to the highway with a faraway stare, accessing a distant and painful memory. “I was married too. An American army ranger. He was stationed here before deploying to Afghanistan. Paktia Province. His unit received intel on a ‘potential’ Taliban stronghold.” She chokes back tears. She swallows bile. “There was nothing ‘potential’ about it.”

Eva’s grief, so palpable that Jonas can almost touch it, fills the small car. He forms condolences in his mind, but they all sound hollow and wrong. A lone tear tracks down Eva’s face. She swats it away.

“I’m sorry,” he says. “I didn’t know. I’m sorry I didn’t ask.”

“Why do you get a second chance when the rest of us don’t? What makes you so special?” There’s a bitterness to her words that Jonas didn’t think she was capable of. A reminder that, in the end, everyone shares the same human shortcomings, the same pain.

“You know I’m not special,” he says with care but also sincerity. “If your husband meant as much to you as Amanda does to me, you have to know why I have to do this.”

“I do. Of course I do.”

“But?”

The question goes unanswered. Silence hangs between them. The next few minutes are filled with the droning of the car’s engine and the rush of traffic.

Finally, Jonas reminds her, “You said you’d help me.”

“This is me helping you,” Eva rebuts. “The fifth and last stage of grief is acceptance. Your wife is dead. You need to accept that.” She turns to him again to make her point firm. “You can’t swim against the tide of the universe.”

The words hit like blows, pummeling Jonas with the truth. With reality. “I don’t believe that,” he whispers.