The Star

- Are you sure he is coming?
- Absolutely.
- I find it hard to imagine. For fifteen years, we don't know anyone who has been able to meet him. I heard from a guy, third-hand information, that he used to live on a small farm in Mormoiron, near Carpentras, and that he later left abruptly because someone had managed to locate him.
- He wants to live "far from the world."
- To that extent! But... why does he live like this?
- You know he was one of the founders of the Institute of Advanced Scientific Studies in Bures-sur-Yvette.
- The Mecca of French science, where all the Nobel Prize winners and Fields Medalists systematically go. He was practically the founder of Algebraic Geometry.
- It can be said categorically that he is currently the greatest living mathematician, in the league of Élie Cartan, both in terms of the volume of his work and its quality. It is also said that a significant part of his mathematical work has not yet been well understood.
- I have also heard that. But why did he literally vanish one day?
- I know the story. He was fundamentally anti-militarist. He once said, "I would rather be shot than wear a uniform." One day, a letter arrived at the IHES in Bures from the scientific services of the army, which was then called the DRET, the Directorate of Research and Technical Studies, now the DGA (Armament Application Delegation), offering a credit of four thousand francs (650 euros). When he saw that paper, he blushed and said, "There's no way we accept a penny from these people!" His colleagues tried to change his mind: "Listen, Alexandre, don't be so stubborn. It will pay for photocopies..."
- And then?
- They didn't take his threat seriously. The vote took place and the four thousand francs were accepted by a majority vote. His face turned gray and as hard as marble. He took a headed paper and simply wrote: "I have the honor to present my resignation" and handed it to the members of the council before walking away. The next day, he didn't show up in his office, nor the day after. The papers started to pile up. There were letters from all over the world.
- He was a Fields Medalist.
- His fame was such that he attracted the greatest mathematicians on the planet to the Institute. For everyone, he was the beacon of Algebraic Geometry, enlightening the entire planet with his brilliance. At first, people thought he was depressed or had run away. At the IHES, he had a staff apartment. After a week, a locksmith was called to open the door. The apartment was empty. They found piles of his papers in a trash can. He had thrown everything away — his notes, books, reports, correspondence.
- Unbelievable!...
- Wait, weeks and months passed without knowing where he had gone. You can't imagine the panic at the Institute. Scientists started making phone calls from all over the world. They had to answer and admit that he had resigned. People wanted to know why he had acted this way, under what circumstances, where he had gone, what he was doing now. The most unbelievable rumors circulated. At one point, people thought he had committed suicide, but some who had met him had to face the truth: he was apparently still alive. We have a letter from him dating two years after his resignation from the IHES, addressing a company that provides organic fertilizers, where he protests, saying that they do not meet the specified standards. It was clearly his signature and, it has to be said, his style.
- And since then?
- Since then, nothing. The greatest mathematician in the world simply vanished one fine day. He simply let the scientific community know that he wanted nothing more to do with that world. He announced, through a letter he sent to one of his former students, his decision to completely withdraw. As people eventually located him in that small village near Carpentras, where he had rented a small farm, they hoped to find him by offering him a new prize, the Crawfoard Foundation Prize. It must have been in the early 1980s. The amount was around forty bricks.
- That's a lot, wow.
- He replied with a very curt letter, which was reproduced in the newspaper "Le Monde," saying that he really didn't see what he would do with that money. Then he left again and no one knows where he went to retire. In the village, he disappeared without a trace.
- But does he still receive his mail?
- At the post office in Mormoiron, they have collected the stamps from the thousands of letters that have been addressed to him from all over the world. He did not leave any forwarding instructions.
- But then, how is it planned for him to have lunch at the cafeteria today?
- Turishev simply said that he would be with him. They're traveling together.
- But... where are they going?
- That's a mystery.
- Does Turyshev know him?
- He was his student a long time ago. It seems that the other one contacted him by phone. We don't know more. We immediately asked if we could sit at their table. Turishev agreed on the condition that, on the one hand, we keep it to ourselves, and on the other hand, no one asks any questions. He made it clear that any remarks regarding mathematics would obviously be excluded. It was either that or nothing.
- Have you seen him?
- Yes, they are in the library at the moment.
- What does he look like?
- Like Hubert Reeves but taller and with glasses.

Lunchtime arrived. Usually, when there was a visitor, the director was supposed to say a few words of welcome. But there, everyone sat down at the table without saying a word. No one dared to speak for fear of making a mistake. It felt like being in a Cistercian abbey. Yet everyone had the impression of experiencing an exceptional moment. Simply being able to tell their colleagues the next day that they had lunch with the greatest living mathematician, the father of Algebraic Geometry, gave them a sort of vertigo and conferred upon them the status of insiders. They imagined the envious expressions of those who, absent that day, had missed such an opportunity. They could always answer, when questioned about a possible exchange of views, "that the master asked them to keep it to themselves." The atmosphere at the table resembled a of Freemasons, a secret society. Suddenly, the silence was broken cafeteria manager, with a joyful expression, went straight to the bearded patriarch.

- Mr. Grothendieck, would you accept, as a souvenir, to write down some equations on this sheet of paper? In exchange, I propose to offer you this meal, for you and your colleagues.

The mathematician gave a contemptuous smile. Someone had already spoken. It's possible that half of the university already knew. Everyone had already finished their coffee. Turishev suggested an immediate departure. Alexandre Grothendieck accepted, but before leaving the table, he took the pen offered to him by the cafeteria manager at the Institute of Mathematics and wrote a few signs on the paper, in a handwriting so small that it was barely readable. The manager received the paper as an invaluable gift. Suddenly, he came back again:

- Would it be too much to ask? What you wrote on this paper, could you... sign it?

- Listen, my friend, I pay for the meals, I don't buy the restaurant...