We have what I assume is an ordinary married sex life—a couple of times a week, motions we have mastered for an economy of time, a guarantee of pleasure, and a solid night’s sleep. Whoever comes first makes sure that the other gets there, too. It is always good, and it is occasionally great. Like just now. When sex isn’t the right word, anymore. It’s more like spilling over the boundaries of your own body to fill someone else’s, and having them do the same to you.

In many ways, this is a microcosm of marriage. There is a lot of Did you use up all the creamer? and Are you going by the post office today? but every now and then, there are moments of transcendence: when you rise in tandem the moment your daughter crosses the stage at fifth-grade graduation; when you glance across the table at a dinner party and have an entire conversation in silence; when you catch yourself looking around at your home and your family and think: This. We did all this.

Brian had fallen for me fast. He once told me that when he was with me, he didn’t fade into the background. Food tasted better. The air was crisper. He said I hadn’t just changed his world. I’d changed the world.

Brian reaches for a dish towel and hands it to me, the messy business of love that no one ever has to deal with in Hollywood. What do they do? he has whispered to me at movies. Sleep in the wet spot? He kisses me lightly and pats the marble counter. “Promise me you’ll scrub this before you cook on it,” he says, and starts to withdraw.

I hook my ankles together and trap him, looking into his eyes. It’s something you don’t do a lot, when you’ve been with the same person as long as I have. You glance, you skim, you catch his gaze, but you don’t really drink in his features as if they are an oasis in the desert. But now, I stare and stare until Brian fidgets, and gives me a sheepish smile. “What?” he asks. “Is there something on my face?”

“No,” I say. But I see it, finally—the wonder. The belief that he might wake up and all of this will be a dream. Oh, there you are, I think. The man I fell in love with.

* * *

—

I MET BRIAN at the communal kitchen in the hospice where my mother was dying. We crossed paths at the coffee machine. I knew, after a few days, that he liked flavored coffee—hazelnut or French vanilla—and that he was a lefty. There was always a residue of graphite on the comma of his hand, as if he’d spent the day writing in pencil.

I brought a lunch snack most of the days I was sitting with my mother, and sometimes I would eat it at the scarred little table in that communal kitchen. Brian was there, too, making mathematical notations that were so tiny I had to squint to see the numbers. They were figures I didn’t understand; factorials and exponents and equations way beyond my AP Calculus memories.

“Good day or bad day?” I asked him. This was the hospice equivalent of How are you doing? which, in hospice, was always: dying.

“Bad day,” Brian said. “My grandmother has Alzheimer’s.”

I nodded. I was grateful, at that point, for my mother’s lucidity.

“She thinks I’m a Nazi, so I figured it would be better if I left the room.” He scrubbed a hand through his hair. “It kind of sucks, you know. To have your body survive the Holocaust and your brain be the part of you that quits.”

“You’re a really good grandson, to be here all this time.”

He shrugged. “She raised me. My parents died in a car crash when I was eight.”

“I’m so sorry.”

“It was a long time ago.” Brian watched me open a bag of Goldfish. “Is that all you’re eating?”

“I didn’t have time to go food shopping—”

He pushed half of his turkey sandwich toward me. “It’s your mom, right?”

It wouldn’t be hard to figure that out, and it still hurt, knowing that someone else had asked questions, had made judgments, had pitied me. “It’s not rocket science.”

“No. Quantum mechanics.”

I glanced up, confused, and found him hunched over his papers again, scribbling.

“You don’t look like a physicist.” I glanced at the sea glass of his eyes, and the hair that kept falling into his face because it was too long.

“How am I supposed to look?”

I felt my face heat up. “I don’t know. A little more…”

“Greasy? Frayed?” He raised an eyebrow. “How about you? What do you do, when someone isn’t dying?”

The way he said it, so frankly and honestly, was the first thing I liked about Brian. No euphemisms, no subtlety. At the time, I found that directness refreshing. But I also couldn’t say the words out loud—that I was an Egyptologist who’d been ripped out of Egypt and who couldn’t see a path back to completing my Ph.D. That, unlike with numerical equations on paper, there wasn’t an easy way to solve my problem.

“I’ve never understood quantum mechanics,” I said, steering the conversation away from me. “Teach me something.”

He turned to a fresh page and drew a tiny circle. “You ever hear of an electron?”

I nodded. “It’s a particle, right? Like, an atom?”

“Subatomic, actually. But for our purposes, you only have to know it behaves like a sphere. And one thing we know about spheres is that they can spin, right? Either clockwise or counterclockwise.” He drew a second circle on the page. “The thing is, electrons are supercool because they can spin clockwise and counterclockwise at the same time.”

“I call BS.”

“I don’t blame you. But, actually, there have been tons of experiments that can only be explained with this phenomenon. For example—imagine taking an opaque screen that blocks out all light. Now cut two little holes in that screen—let’s call them slit 1 and slit 2. If you shine a laser beam onto the slits, and you block slit 1, you’d expect to see a little blotch of light on the wall in the distance aligned with slit 2. If you block slit 2, you’d expect to see a little blotch of light on the wall in the distance aligned with slit 1. What happens when we open both slits at the same time?”

“You see two blotches?”

His eyes lit up. “You’d think so, right? But no. You get a whole row of blotches of light uniformly spaced out in various intensities. It’s called an interference pattern. The only way physicists can explain it is that the light that comes out of slit 1 must be interacting with the light that comes out of slit 2, because we know that when only one slit is open you get a single blotch on the wall…when the other slit is open you get a single blotch on the wall…and when they’re both open, you get something you’ve never seen before. Then Einstein came along and told us light isn’t a jet stream, it’s all individual particles, so maybe the pattern comes from individual particles from different slits hitting each other. Scientists slowed the laser to a point where only one photon was going through a slit at a time, figuring that the weird pattern would disappear. But it didn’t. And physicists were left with the explanation that the one photon actually does go through both slits simultaneously, interfering with itself. Even though every evolutionary instinct bred into us revolts against the idea.” He glanced at me. “That interference phenomenon is what makes your laptop work, in case you still think I’m bullshitting.”

“What does this have to do with the electrons?” I asked.

“We know they spin both clockwise and counterclockwise,” Brian said. “So let’s say you put an electron in a box. There’s a little trigger next to the electron that will activate if the electron spins clockwise, but it won’t activate if the electron spins counterclockwise. If the trigger activates, it will send a signal to a gun, which will fire, and kill a cat.”

“That’s a big box.”

“Work with me,” Brian said. “So if the electron goes clockwise…”

“The trigger activates, the gun goes off, the cat dies.”

“And if the electron goes counterclockwise?”

“Nothing happens.”

“Exactly.” He looked up at me. “But what happens if that electron spins both clockwise and counterclockwise at the same time—as we know it can?”

“Either the cat is dead or it isn’t?”

“Actually,” Brian corrected, “the cat is both alive and dead.”

“How postapocalyptic,” I murmured. “Nice story, but I’ve never seen a zombie cat.”

“That’s pretty much what Niels Bohr said, too. He knew that the math said this was happening, but he had never seen a live-dead cat either. So he figured that there had to be something special about the act of observation that made the cat stop being both alive and dead, and instead become just alive or dead.”