Tesla arrived in Paris in April of 1882, two months after the park, and went to work for the Compagnie Continentale Edison at the Villa des Ternes the following Monday. The pay was two hundred francs a month. The rent on his attic room in the Marais was fifty. He walked to work each morning along the rue des Francs-Bourgeois, counting his steps — three, six, nine — and he arrived at the gate of the Villa at seven o'clock precisely every morning and left at seven o'clock precisely every evening and ate, when he remembered, at an Italian cafeteria behind the Gare de l'Est where a bowl of bean soup cost eighteen sous, and the rest of the time he was in his attic room drawing the motor, because when he was not drawing the motor he could see the door.
The door had begun, since Budapest, to come into rooms with him.
It did not come every day. It came perhaps once a week. It would come at some hour he could not predict — walking back to his rooms in the evening, or reading a novel by a cold supper, or, once, in the middle of a lecture by the Continental Edison chief of design, in which Tesla, who had been standing with his notebook open and his pencil poised, had looked up from the page to find the air in the room half a foot in front of his face leaning — the way the air in the field had leaned at four o'clock on an August afternoon in 1861 — out of the way of something that was coming through.
He had closed his eyes.
When he opened them the air was air again. The chief of design was still speaking. The pencil was still in his hand. No one in the room had noticed. The door had come into the Continental Edison lecture hall at the Villa des Ternes, had looked in, and had gone out again.
He had understood, by then, that the door came to him when he thought too hard about it.
The solution, he had also understood, was not to stop thinking about it. The solution was to redirect what he thought about it. If he thought about the door as a door — as a thing that had opened once and would open again if he willed it — it came to him. If he thought about the door as an apparatus, as a field of forces that could be described and designed and built, it did not come. The door was either a ghost or an engineer's problem. When he treated it as a ghost it visited him. When he treated it as a problem it kept a professional distance.
So he treated it, for fifteen months in Paris, as a problem.
He kept two notebooks. The first notebook was for the Villa des Ternes. It was the dull one. It contained revisions of wiring schemes for the Edison incandescent plant at the Gare du Nord, and the Gare Saint-Lazare, and the Grande Opéra — all of which he had been sent, in his first year, to troubleshoot and improve, because he could improve any installation in his sleep and the Villa had quickly understood this.
The second notebook was for the attic. It was leather-bound, small enough to fit in the inside pocket of his coat, and it was private. It did not contain the AC motor. The AC motor he kept in his head. It contained instead the other thing — the larger thing, the slow thing, the thing he had been building since the candle in the boys' room in Smiljan in August of 1861. In the second notebook he called it, without ceremony, the Aperture. He drew it. He drew its dimensions. He drew it in a four-pole configuration and a six-pole configuration and — in a diagram that filled six facing pages in a single night — a sixteen-pole configuration in which the poles were not discs but cylinders sunk into the earth, each one terminating in a copper plate and connected back to a central primary by a spoke of iron rod.
The sixteen-pole configuration was, even on the page, almost right.
He had not yet fired an Aperture. He knew he could not. He did not have the materials, and he did not have the ground, and above all he did not have the privacy. The Villa des Ternes was a glass house. Everyone watched everyone. Batchelor — Charles Batchelor, Edison's man from Menlo Park, who had come over to Paris the year before to supervise the European operations and who had taken an immediate, grave interest in Tesla — Batchelor watched Tesla more closely than anyone. Batchelor was, Tesla suspected, in love with him in a distant, professional way. Batchelor would have been horrified by the description, but it was true. Batchelor spoke of Tesla as of a thoroughbred he was considering bringing to America. Batchelor, in late 1883, began writing letters to Edison in New York that mentioned Tesla by name more and more often.
Tesla liked Batchelor. Batchelor was not in his way. Batchelor was on his road.
The man who was in his way was named Pryce.
Arthur Pryce was an English engineer, twenty-nine years old, a bachelor, a second son from Surrey who had come to Paris two years before Tesla and who had failed, in those two years, to distinguish himself in the way he had intended. Pryce was not stupid. Pryce was also not especially clever. He was the kind of competent young man who, in any office, mistakes another man's brilliance for a trick being played on him. He had decided, within three months of Tesla's arrival at the Villa, that Tesla was concealing something. He was not wrong. Pryce had simply decided, on the evidence of his own limitation, that what Tesla was concealing was a private patent — some improvement, some dynamic, some trick of armature design that Tesla was going to take with him to America and use to make his fortune without the knowledge or the consent of his present employers.
Pryce had begun to follow him.
Tesla noticed on the second evening.
He had been walking home along the rue de Rivoli at nine o'clock in the evening, in light spring rain, with his coat pulled against the weather, and he had noticed, at the corner of the rue du Pont-Neuf, a man stop suddenly on the opposite pavement and bend to re-tie a boot that did not require it. He had noticed, two minutes later at the Place du Châtelet, the same man cross to the same pavement on which Tesla was walking, thirty paces behind him. He had noticed, turning into the rue des Francs-Bourgeois, that the man had turned with him.
The man was Pryce. Tesla recognized him by the coat. The coat was a fawn-colored mackintosh of a kind that no Frenchman owned and that only one Englishman at the Villa wore.
Tesla did not increase his pace. He did not slow. He walked the remaining seven blocks to his door at his ordinary rate and he let himself in and he went up the three flights to his attic and he lit his candle and he sat at his drawing table and he did not look out the window. If Pryce was across the way, Pryce was welcome to be across the way. There was nothing to see from his window but a man working on a motor scheme by candlelight, which was what any engineer in Paris did.
But the following night it happened again. And the night after that. On the third night Pryce was bolder. He did not cross the pavement and stand opposite. He waited, instead, in the archway of the building next door to Tesla's, and when the candle in Tesla's attic window went out at one in the morning — an unusual hour; Tesla had extinguished it on purpose, to see what would happen — Pryce emerged from the archway and stood for three minutes with his eyes on the window, waiting for Tesla to go out. Tesla did not go out. Pryce eventually walked away.
On the fourth night Tesla sat down at his drawing table and considered what to do.
He was, by this point, twenty-seven years old. He had been building a particular apparatus in his head for twenty-two years. He had been refining the Aperture in his private notebook for eighteen months. He had been at the Villa des Ternes for fifteen months and he would be at the Villa des Ternes, he calculated, for perhaps six more — long enough to save the money to go to America, and no longer. Arthur Pryce was a man who had decided, on the wrong evidence, that Tesla had a commercial secret. Pryce would not rest until he had either proven Tesla had one or proven that Tesla did not. Pryce would, at some point, break into Tesla's attic.
It might be tonight. It might be in three months. It would be.
And when Pryce did — because Tesla was a careful man, and because he did not leave the Aperture notebook in the attic, but carried it on his person always, in the inside pocket of his coat — Pryce would find nothing. And Pryce would conclude that Tesla had been bluffing. And Pryce, unsatisfied, would follow Tesla a little longer, and be a little more aggressive, and, eventually, do a thing that would draw the attention of the Villa's management — perhaps an accusation, perhaps an open quarrel, perhaps a letter to Edison in New York — that would become, Tesla saw, a stone in his path that he could not afford.
So.
Tesla considered, on the fourth night, the ethics.
He had never killed a man. He had never wished to. The Aperture had taken, since 1861, exactly one man — Henrik Szabó at the Edison Machine Works, which was in the future, and which Tesla did not yet know about because he had not yet sailed — and one man was going to become two men soon, because Tesla was going to need to fire a small Aperture in Paris to confirm a calibration, and he would not fire it without a subject on the plate. He had intended the subject, in his planning, to be a stray dog.
He looked, that fourth night, at the Paris roof-line across the street. He looked at the archway. He did not see Pryce. Pryce had, this evening, either not come or had concealed himself better.
He thought: a stray dog, or Pryce.
He thought it calmly. He noted that he was thinking it calmly. He noted that the calmness troubled him — not because he wanted to feel disturbed, but because he did not. The boy of five in the field behind the parsonage had seen a door open and had said I will find it; he had not said I will fill it. The boy of five had been an innocent. The boy of five had wanted his brother back.
The man of twenty-seven had wanted his brother back for a long time and had wanted, he now admitted to himself, other things as well.
He wanted, specifically, to know. He wanted to know where Dane was. He wanted to know what was on the other side. He wanted to know whether the cold that waited behind the door was an absence of warmth or a presence of something cold. He wanted, when he fired his Aperture at scale, to be able to verify — and he could not verify with a stray dog, because a stray dog could not, when called, come back and tell him.
He wanted to know whether a man, once sent, could return.
Pryce was such a subject.
Tesla sat at his drawing table. He watched the candle.
He thought of his father, placing two fingers on his mouth nine years earlier, in the room in Gospić, on the morning of his fifth of December. You will not say those words in this house, ever again, while I am alive. He thought of his mother, spoon to mouth, three sips and a pause. He thought of Dane, cantering in gold light, mid-laugh, mid-flourish. He thought of the cold behind the door.
He closed the Aperture notebook. He stood.
He said aloud, in the small attic room, to no one:
"No."
He said it again: "No."
He said it a third time, very carefully: "No."
He opened the notebook to the next blank page and he wrote, in a small careful hand — the same hand he had used in 1861, which had not changed because handwriting does not much change in a person — four sentences:
I will not use Pryce. I will not use anyone. I will fire a dog, as planned. I will go to America with no man on my conscience.
He underlined the last sentence.
Then he blew out the candle, and he went to bed, and he slept dreamlessly, and in the morning he got up and put on his coat — with the Aperture notebook in its inside pocket — and he went to the Villa des Ternes.
At the Villa, that morning, he sought out Charles Batchelor in his glass-walled office.
Batchelor was at his desk, in his shirtsleeves, with his jacket over the back of his chair and his cuffs rolled. He was writing a letter. When Tesla knocked, Batchelor looked up, set down his pen, and gestured to the chair.
"Tesla. Come in."
Tesla did not sit.
"Mr. Batchelor," he said, "I have been told you are writing to Mr. Edison about me."
Batchelor's eyebrows went up. He laughed, in his flat Mancunian laugh. "I am. I have been. For some months. Who told you that?"
"Everyone," said Tesla, which was not untrue.
Batchelor gestured again to the chair. This time Tesla sat.
"Mr. Batchelor," Tesla said. "I should like to go to America."
Batchelor looked at him for a long moment. Batchelor was a serious man. Batchelor, in his forty-second year, was the kind of Englishman who, having spent fifteen years in Menlo Park and two in Paris, had gone practical at the root; he admired genius without being confused by it; he understood that geniuses had to be managed the way difficult mares were managed, with firmness and sugar.
"Nikola," Batchelor said. "I am prepared to send you. I have been preparing to send you. I had thought, to be candid, to send you in November. Would you consent to June?"
"I would consent to April."
Batchelor laughed again. "You Hungarians."
"Serbs."
"Serbs. Very well. I will write to Edison today. I will recommend April. I will write him a letter so warm it will embarrass us both."
"Thank you, Mr. Batchelor."
"Nikola."
"Yes."
"Why, particularly, now. You were to stay through the autumn on the Opéra installation."
Tesla, who had prepared for this question on the staircase on his way up, said: "There is a man here who is hindering me. I would rather be in New York than here with him."
Batchelor's face, behind his mustache, did a very small interesting thing.
"Pryce," he said.
"You know."
"I know. He has made — representations — to Monsieur Rochefort. Nothing serious. I had been planning to ask him to leave the company in the autumn for unrelated reasons. If he is a reason for your going, he is also a reason for his going. I will have him out by the first of August. You, in April, to Mr. Edison. And we will say no more about him."
"Thank you, Mr. Batchelor."
"Tesla."
"Yes."
"What would he have found, if I had not."
Tesla looked at Batchelor.
Batchelor's eyes were small and brown and very steady.
"Mr. Batchelor," Tesla said, "he would have found nothing. He would have found a single notebook of drawings of a motor. I carry it always in this coat."
"The motor."
"The AC motor."
"Which is the thing about which I have been writing to Mr. Edison."
"Yes."
Batchelor nodded. He picked up his pen. He tapped it on the blotter three times — unconsciously, Tesla saw; a quirk Tesla had not noticed in him before — and he said, "Go back to work, Nikola. I will write the letter."
Tesla rose. At the door he stopped.
"Mr. Batchelor."
"Yes."
"He has been following me at night."
Batchelor's pen paused.
"Arthur?"
"For three nights in a row."
Batchelor looked at him for another long moment. Then he said, very quietly, in the flat Manchester voice: "I will take care of it, Tesla. Go to work."
Tesla went.
On the ninth day of July, 1883, Arthur Pryce did not arrive at the Villa. By the twelfth he had not returned. By the fifteenth Batchelor had posted an advertisement for a replacement draftsman, and the gossip at the long table at the Italian cafeteria was that Pryce had disappeared one Saturday night at the end of a Belleville bal — a working-class dance on the slope above the Gare de l'Est — and that the French police, having looked briefly, had concluded Pryce had returned to London.
Pryce had not, in fact, returned to London. Pryce was never seen again. A trunk of his personal effects sat at the Villa for four months, was sent to a cousin in Guildford, and was eventually sold at auction to pay for storage.
Tesla — who had not seen Pryce since the fourth evening, and who had not fired the Aperture that week, and who had not, to be clear, done anything whatsoever to Pryce, because he had made his choice at the drawing table and had kept it — heard the gossip at the long table and ate his bean soup and said nothing.
But that night, back in his attic, with the Aperture notebook in front of him, he wrote a short line beneath the four sentences he had underlined in the small hours of the first of July:
Someone else may use this apparatus. I am not the only one.
He drew a line under the line.
He did not, in that hour or any hour after, know what he meant. Batchelor, for his part, in a letter to Mr. Edison dated the sixteenth of July, wrote that he was sending a young Serbian engineer in the spring, and that the young Serbian engineer was a man of the finest character; and Batchelor, setting down the pen, stood and looked out the window of his glass office for a long time at the Paris evening, and did not, because he could not have said it to himself in so many words, admit that he had taken care of the man named Arthur Pryce in a way that he would not ever, on any afternoon in the rest of his life, tell anybody about.
There were not, in 1883, many doors in the world that Nikola Tesla had built.
But there were more than one.
And the man in Paris who had hoped, perhaps, to find one of the young Serbian's drawings, had instead found a room — in a cellar behind the Belleville bal — and a chair bolted to a brass plate in the floor, and an engineer he had not known was an engineer at all, sitting across from him in the quiet, smoking a small cigar, and saying, in Manchester English:
"Arthur. I do apologize. But this is for the company."