I live alone in a small flat on the fourth floor in Buenos Aires, on Belgrano Street. A few months ago, one evening, someone knocked on my door. I opened it and saw a tall man standing there. He wore grey clothes and carried a grey suitcase. His face did not look special to me, maybe because I have weak eyes. He looked like a foreigner. At first, I thought he was old, but then I saw his thin, almost white hair and realized he just looked old.I asked him to come in and pointed at a chair. He sat down quietly and looked serious. After a moment, he said, “I sell Bibles.” I told him I already had many Bibles at home, even some rare ones. I said I didn’t really need another Bible.He waited for a bit, then said, “I don’t only sell Bibles. I have a very special book I found near Bikaner, in India. You might like to see it.” He opened his suitcase and took out a book. The book looked old and was covered with cloth. It was heavy, and I saw “Holy Writ” and “Bombay” written on its side.I said maybe it was from the nineteenth century. He just said he didn’t know how old it was.I opened the book to a random page. The writing looked strange to me. The pages were worn out and not printed very nicely. The text was in two columns, like some Bibles. The numbers at the top of the pages were in Arabic numerals, and they looked very odd. On one page, I saw a small picture of an anchor, drawn simply, like by a child.The man said quietly, “Look at the picture carefully. You will never see it again.” I closed the book and then opened it again, trying to find the anchor picture, but I could not find it no matter how hard I looked. I tried to act normal and said, “This looks like some Indian holy book.”He said, “No. I got this book in exchange for some rupees and a Bible from a man who could not read. He thought the book was magical. He called it the Book of Sand, because, like sand, it has no beginning and no end.”He then asked me to try and find the first page. I tried, but every time I put my thumb near the beginning, more and more pages came between my thumb and the cover. I could never reach the first page. He asked me to find the last page, but I couldn’t do that either. It was impossible.The man said softly, “It seems impossible, but it’s true. The book has infinite pages. No page is first, and no page is last. I don’t know why the numbers are so strange. Maybe it’s to show that in an infinite series, any number is possible.”He started thinking aloud, “If space is infinite, we could be anywhere. If time is infinite, we could be at any time.” His strange thoughts made me feel a little annoyed. I asked him if he was religious. He said he was a Presbyterian and felt he hadn’t cheated the man he got the book from.We talked some more, and I found out he was from the Orkney Islands in Scotland. I said I liked Scotland because I enjoyed reading books by Stevenson and Hume. He corrected me, saying, “You mean Stevenson and Robbie Burns.”As we talked, I kept looking through the strange, endless book. I asked if he wanted to give it to a museum, but he said, “No, I’m offering it to you,” but he asked for a lot of money.I told him I couldn’t pay that much. Then I had an idea. I offered him my pension money and my old Wiclif Bible, which was a family treasure. He was happy with the deal and didn’t even count the money. He took my Bible, and I took the Book of Sand.After he left, I thought about where to keep the book. I decided to hide it behind some other old books on my shelf. That night, I couldn’t sleep. At three in the morning, I turned on the light and started looking at the book again. On one page, I saw a picture of a mask and a very large number at the top.