In the winter of 1925, when the last nickelodeons were still flickering black-and-white ghosts onto wet Broadway pavement, Julian Delaney was twenty-three years old and had never seen anything golden except the tip of a dollar bill sliding across a counter.

His father's family had come from Naples with a trunk full of nothing but a grandmother's recipe for bread and a photograph of the bay at sunset. Jules grew up on a third-floor walk-up on Sullivan Street, where the winters bit through brick walls and the sound of jazz drifted up from the speakeasies below like a prayer you weren't supposed to hear.

He worked as a runner for Harrington & Pryce, a brokerage firm on Broad Street that occupied three floors of a building where the doormen knew your name and the walls smelled of mahogany and other men's money. Jules delivered ticker-tape slips and stock quotations and, on particularly glamorous afternoons, carried champagne flutes to the partners upstairs. He watched them with the rapt attention of a boy at a fairground, watching the carousel spin just out of reach.

It was in that mahogany-and-champagne world that he first heard the name Isabella Moretti.

"Moretti? Some girl from Columbia? They're sending a woman to lead a reflector project? I'll drink to that—after I swallow."

That was from Mr. Harrington himself, who had a way of pronouncing every word like it was a joke he'd told a thousand times and still found amusing.

Jules didn't drink. But he made a note of the name, as one might make a note of a song that plays just once over a distant radio and then is gone.

He found her three weeks later at a lecture hall on Morningside Heights, squeezed between a boy from Princeton who smelled of bay rum and a girl from Radcliffe who was taking notes in a hand so precise it looked like it had been printed. Isabella Moretti stood at the podium in a suit the color of midnight, her dark hair pinned severely back, and spoke about orbital mechanics the way a musician might speak about harmony—as something beautiful that existed whether anyone bothered to listen or not.

The Golden Disc, she called it. A massive parabolic reflector, silvered on one face, designed to sit in geosynchronous orbit above New York and throw sunlight back onto the city like a lighthouse throwing beam across dark water. Funded by a syndicate of Wall Street billionaires who believed, with the unshakeable faith of men who had made fortunes by believing in things nobody else could see, that eternal daylight would double the value of Manhattan real estate.

"It is not merely a mirror," she said, and in that moment Jules understood something he had never understood before: that a woman could speak and her words could be gold, too.

After the lecture, he approached her at the edge of the stage, where she was gathering papers with hands that shook just slightly—nerves, or perhaps the cold, or perhaps the weight of three hundred men in that room who had spent her entire career telling her she shouldn't be there.

"I'm Jules Delaney," he said. "I work on Broad Street. And I want to see it."

She looked up at him with eyes the color of espresso, dark and warm and entirely unreadable. "See what?"

"The Disc. The thing you're building. I want to see it."

She studied him for a moment, and then she smiled—not the thin smile of a woman used to being tolerated, but a real smile, the kind that surprised even the person wearing it.

"Then come tomorrow. Six in the morning. The shipyard in Brooklyn. Don't be late."

He wasn't late. He was there at five-thirty, standing in the cold dark of the Brooklyn waterfront, watching the silhouette of the Golden Disc rise from a cradle like the prow of a ship. It was wider than a football field and thinner than a man's hope, covered in a surface so reflective it made Jules uncomfortable to look at it directly, as one is uncomfortable to look at the sun.

Over the next months, he came every day. He watched the engineers weld seams with torches that threw orange light across the water. He sat with Isabella in a drafty canteen drinking terrible coffee and listening to her talk about angles and velocities and the mathematics of light. He fell in love with her the way one falls in love with jazz—in small, incremental betrayals of the heart that accumulate until one morning you wake up and discover you can no longer live without it.

She never said she loved him back. But she didn't say she didn't, either, and in the Jazz Age, that was as close as anyone ever got to certainty.

When the Golden Disc was finally launched, Isabella went up with it as its lead physicist. Jules, using every ounce of charisma and charm he had ever watched Harrington & Pryce partners wield, convinced the Orbital Services Corporation to hire him as a maintenance technician—a job that meant living aboard the station attached to the Disc, spending his days cleaning the silver surface and making adjustments to the attitude thrusters, and his nights floating by the observation cupola with Earth hanging below him like a blue candle.

Isabella was there too, not as a scientist this time but as the woman who shared his oxygen and his silence and the terrible beauty of looking down at the world from a place where no one could see you be anything less than extraordinary.

They did not talk much in those early months. There was a lot to see. The Golden Disc rotated slowly, and its silver face turned toward the sun like a flower turned toward God. Jules worked the edge of it with magnetic boots and a silk cloth, wiping away the microscopic debris of space—micrometeoroid dust, the exhaust of spent boosters, the invisible snow of human expansion into the void. Sometimes Isabella joined him, floating at his side, and they worked in silence side by side, two figures on an infinite plane of silver beneath a sky so black it looked painted.

"Why did you come up here?" she asked him one evening, when the Earth was turning and New York was a gold thread winding through a dark coastline.

"To earn a living."

"That's not true."

He thought about it. The truth, when he spoke it, sounded like something Isabella might write in a journal: "Because you showed me that there are things bigger than Sullivan Street. Bigger than Broad Street. Bigger than the idea that I should be happy with something small just because it's the size of me."

She reached out and touched his hand, and in the silence of space the touch was louder than any music he had ever heard.

But the Jazz Age had a way of making everything beautiful and temporary, as though the whole world were a dance hall where the floorboards were polished for one last dance and then the building would be torn down. Jules knew, even as he held Isabella's hand in the cupola while Earth spun below them, that this was not a permanent arrangement. Stations were temporary. Projects were temporary. Nothing in space lasted forever—not the satellites, not the fuel, not the people who tended them.

He was offered a return trip in the autumn of 1927. The station's life support systems were being decommissioned; a new model was coming up, more efficient, more automated, and notably less interested in hiring men who spent their days wiping mirrors.

The night before the transport ship docked, Jules and Isabella floated together at the edge of the Disc. The Earth was a deep blue below them, darker than it had any right to be, as though all the oceans of the world had pooled together for one final view of the two people who mattered.

"You're leaving," she said. It wasn't a question.

"Yes."

"Why?"

He turned to look at her. Her hair had come loose from its pins and floated around her head like a halo made of smoke. In the reflection of the Disc, she was a silver ghost superimposed on a woman, and the effect was so beautiful it made his chest ache.

"Because if I stay, I'll want to stop," he said. "And I can't stop. You know that. When the music stops, the dance ends. That's how it works. You don't keep dancing after the band plays the last note. You just—keep moving your feet, and it looks foolish."

She was silent for a long time. The station hummed around them—the faint vibration of pumps and fans and the machinery that kept two human beings alive in a place where no human being was supposed to live.

"Do you love me?" she asked.

"Yes."

"Will you remember me?"

"I'll never stop."

She smiled, that same surprised smile, the one that had appeared in a lecture hall on Morningside Heights five hundred miles below and three years ago and yet felt like it had always existed, waiting for the exact moment it was needed.

"Then go," she said. "The ship is docking in the morning. Take it. And know that while you were up here, cleaning my mirror, you were the most beautiful thing I had ever seen."

He left at dawn. The transport ship detached from the station and began its descent through the atmosphere, and through the porthole he watched the Golden Disc shrink behind him until it was only a bright point of light, like a star that had fallen out of its proper place and was trying to find its way home.

He returned to New York and returned to Broad Street, where the partners still drank champagne and the walls still smelled of mahogany. But he did not look at the money the way he used to. He looked at the sky.

Every evening, when the office cleared and the ticker tapes stopped their endless chatter, Jules walked to the roof of the building and looked up. He knew that somewhere above the clouds and the smog and the telephone wires, the Golden Disc was still turning, still throwing its borrowed sunlight back onto the city, still reflecting the faces of people who would never know that a man from Sullivan Street had stood on its edge and watched the world turn.

He never saw Isabella again. She stayed in orbit longer—two more years, then three—and then the station was finally retired and she returned to Columbia, where she wrote papers on orbital reflector theory that nobody read and gave lectures that nobody attended. She became, in the way that so many brilliant women did in that era, a rumor. A story people told each other in hushed voices at faculty gatherings: "Did you hear about Dr. Moretti? She went to work for NASA now. Or was it Boeing. Or maybe she just disappeared. Nobody knows."

Jules knew. He knew every detail, because he had been there when she packed her laboratory drawers and sealed them in cardboard boxes and walked out of the building without looking back.

On the night of the crash, when the stock market on Wall Street went down like a building on fire and men jumped from the thirtieth floor and the streets filled with men in expensive suits who had nothing left to lose, Jules stood on his rooftop and looked up and thought of Isabella and the golden disc and the way she had looked at him in the observation cupola, when Earth was blue beneath them and the silver plane stretched out in every direction like an ocean made of light.

The music had stopped. The dance was over. But for a few brief years, they had moved together beneath a sky that was not the sky anybody else saw, and that was enough. It had to be enough. In the Jazz Age, enough was all anybody ever got.