Dr. Arthur Pemberton was an advertising executive who specialized in television commercials in 1956 Connecticut, and his most brilliant campaign was the one he created for himself without knowing he was creating it, in a series of nested realities so perfectly layered that he did not realize he was trapped until the last layer had closed behind him like a book being shut.

It started with a client. The Maxwell Electronics Corporation wanted a commercial for their new television set, a handsome walnut-cabinet model with a twelve-inch screen that they claimed could bring the world into your living room. Arthur's agency, Whitfield and Cross, won the account with a pitch that Arthur would later describe as the most honest piece of advertising he had ever done.

The world is not in your living room, he told the Maxwell executives. Your television set is a door. Every time you turn it on, you walk through. The question is not whether you want to walk through. The question is what you find on the other side.

The commercial was simple. A family sits around the television in their Connecticut living room. The screen shows a forest. The father reaches out and touches the screen, and his hand goes through it, into the forest. The camera pulls back to reveal that the living room is itself a television screen, and the family watching it are sitting in front of another television, and so on, to infinity, each layer slightly different, each one real, each one false.

The commercial aired on November 14, 1956, during the World Series. It was hailed as a masterpiece. Arthur Pemberton was interviewed on a television program called This Week, where he explained his creative process to a national audience.

I was thinking about mirrors, he said. You put two mirrors facing each other and you get infinite reflections. I wanted to do that with television. I wanted the viewer to look at the screen and realize that the screen was looking back.

The interview was broadcast live. In the studio, there were two large mirrors on either side of the set, placed there by accident — the set designer had misread the floor plan. As Arthur spoke, the camera angle captured the mirrors reflecting each other, creating an infinite regress of Arthur Pemberton sitting in a studio on a television show about television, reflected in mirrors that reflected a television show about television reflected in mirrors, ad infinitum.

The director did not notice. The audience did not notice. But the footage exists, in the archives of CBS, and anyone who watches it with a patient eye can see it: the moment when Arthur Pemberton, mid-sentence, stops and looks at the mirrors behind him with an expression of such profound confusion that the camera operator — a young man named Frank DiAngelo, who would go on to direct twenty years of major network programming — felt the need to pause the tape for exactly two seconds before resuming.

Arthur never knew about the pause. He went on to win three Clio awards and a Cannes Lion and a modest amount of fame within the advertising industry. He bought a house in Westport, Connecticut, with a view of the harbor and a garden his wife Eleanor had planted with roses and hydrangeas. He drove a Chevrolet to his office in New York and came home for dinner at six o'clock every night, except when he did not, because sometimes the work took him late, and sometimes he stopped at a bar on Madison Avenue and had a whiskey and thought about mirrors.

The first sign that something was wrong came in January 1957, when Arthur dreamed that he was watching himself on television. In the dream, he was sitting in his living room, the new Maxwell television set glowing in the corner, and on the screen was a man sitting in a living room, watching a television, and on that television was a man sitting in a living room, and so on. Arthur tried to stand up and leave the room, but he could not move, and the man on the screen could not move, and the man on the screen's screen could not move, and the whole infinite chain was frozen in paralysis.

He woke up sweating. He told Eleanor about the dream over breakfast. She smiled and kissed his forehead and said, You've been working too hard, Artie. You need a vacation.

He did not tell her about the second dream, two nights later, in which he was a television set and his wife was watching him and he could feel her watching him and he wanted her to look away but he could not look away either because he was a television and that was all he was, he was a screen and his only purpose was to be watched.

The third sign was more subtle. Arthur began to notice that his conversations had a scriptural quality. His colleagues at the office used phrases that he had used in commercials. His wife used phrases that he had used in interviews. He would catch himself repeating copy from an advertisement mid-sentence, as if the advertising had seeped into his thinking and was using him to express itself.

He mentioned this to his friend and fellow copywriter Harold Green, over drinks at a bar called the White Horse, which was on Forty-Sixth Street near Times Square and smelled like beer and cigarette smoke and the faint chemical tang of the neon sign in the window that said OPEN in letters that never went out.

Harold listened to Arthur talk about scripts and mirrors and the feeling that his life was being written by someone else, and he nodded thoughtfully and said, You know what that is?

Terror, Arthur said.

No. It's called craft. You've become so good at advertising that advertising has become you. That's not possession, Artie. That's mastery.

Arthur did not feel mastered. He felt nested. He felt like a set of Russian dolls, each one containing a smaller one, and he was not sure which layer was the real one. The outer layer? The one in the house in Westport? Or the innermost one, the tiny one at the center, the one that had been born before advertising and before television and before mirrors, the one that had just been a person and wanted to be a person and now did not know if personhood was something you could own or something that owned you.

He went to see a psychiatrist, a man named Dr. Samuel Levine who practiced in an office above a pharmacy on Post Road and charged twenty-five dollars an hour, which was a lot of money in 1957 and which Arthur paid without complaint.

Dr. Levine listened to him talk about dreams and scripts and the feeling of being a screen. He wrote things down in a small notebook with a gold pen. When Arthur had finished, Dr. Levine closed the notebook and said something that Arthur would carry with him for the rest of his life.

Arthur, he said, there is a French philosopher named Jean Baudrillard — well, not yet. He will be born in twenty years. But he has a concept that is useful for you. He calls it the map and the territory. The map is the representation of the territory. Usually, the map comes after the territory. But sometimes, the map comes first, and the territory is built to match the map. And sometimes, the map becomes so detailed and so compelling that people forget there was ever a territory. They live inside the map.

You're living inside a map, Dr. Levine said.

How do I get out? Arthur asked.

You don't, Levine said. There is no out. There is only the map, and you can either be aware that you are living in it or you can not be aware. The advertising industry is a map. Television is a map. Life is a map. The question is whether you are the cartographer or the traveler.

Arthur went home and sat in his living room in front of the Maxwell television set. It was turned off, a black screen reflecting his face back at him, and for a moment he did not know if he was looking at a reflection or a recording or something else entirely.

He turned the television on. The screen filled with static, white noise, the sound of the airwaves between stations. He watched the static for a long time, and in the static, he thought, he saw something. Not a reflection. Not a recording. Something that looked like the beginning of a map, drawn line by line in the white noise of a dead channel.

He did not turn it off. He sat there until the clock on the mantle told him it was two in the morning. He sat there until the roses in Eleanor's garden had stopped receiving moonlight and the house had gone quiet and the entire world was sleeping.

He turned off the television. He went to bed. He dreamed that he was writing a commercial for a television company, and the commercial was about maps and territories, and at the end of the commercial, the tag line appeared on the screen in white letters against a black background:

The World Is A Screen. And You Are The Signal.

He woke up at dawn, wrote the tag line in a notebook, and never spoke of it again.

He went on living inside the map for another thirty-two years, working in advertising, winning awards, buying houses, driving Chevrolets, and sometimes — late at night, alone in his office, with the lights off and the city glowing through the window — he would turn on his television set and watch the static and feel, just for a moment, the thin and shimmering boundary between the map and the territory, between the screen and the signal, between the man and the role he had played so perfectly that he had become it.

When he died in 1988, Eleanor found the notebook in his desk drawer. It contained the tag line from the dream: The World Is A Screen. And You Are The Signal. Underneath it, in smaller letters, he had written: I am the signal. I am the signal. I am the signal. Thirty-two times.

She also found a letter addressed to her, written the week before he died, in which he explained that the infinite regress of the mirrors in the CBS studio had not been an accident. He had placed them there intentionally. He had designed the camera angle to capture them. He had wanted the national audience to see, for just a moment, that the man they were watching on television was himself reflected in the mirrors, and the reflection was reflected in the mirrors, and the reflection of the reflection was reflected in the mirrors, and so on, and he wanted them to see that Arthur Pemberton was not a man sitting in a studio on a television show about television. He was an infinite regress of a man sitting in a studio on a television show about television, and he had been an infinite regress for thirty-two years, and he had never stopped being one, and the only thing that had changed was that he had finally noticed.