It is a story which out-Dan-Browns Dan Brown, a tale of Italian mediaeval courts, spies, intrigue, and, at its heart, an extraordinary Jewish scholar, Abraham Ben Mordecai Farissol.
Farissol, who lived between 1469 and 1528, was the author of a remarkable manuscript, Iggeret Orhot Olam, or Treatise on the Ways of the World. On July 10, Sotheby's in London is selling Farissol's work, the only one in private hands, and famous as the first Hebrew manuscript to mention America and the possibility of Native Americans being one of the lost tribes of Israel.
Dr Timothy Bolton, Sotheby's specialist in mediaeval manuscripts, can barely contain his excitement about the manuscript, probably written in 1524.
There are only five known copies of the Farissol manuscript - one in Oxford, one in Budapest, one in Parma and one in Florence - but the Sotheby's example is the only one which scholars say carries a delicious "extra" - a sketch of America, almost certainly added to the manuscript by Farissol himself, after the scribe Joseph ben Abraham Finzi Delinyago presented him with the finished version.
Farissol had unparalleled access to the powerful Italian Renaissance courts of Lorenzo di Medici and Ercole d'Este, the Duke of Ferrara. It was a time, says Dr Bolton, "when the Italian dukes were just losing their power. But they were fascinated by what the Portuguese and Spanish adventurers were achieving."
So fascinated was Ercole d'Este, who believed that there was almost certainly an as yet undiscovered New World, before Christopher Columbus set out on his voyages, that he employed spies to keep him informed about Columbus' s discoveries.
Lorenzo di Medici was also desperate to know what the new explorers were discovering. In Iggeret, Farissol records that he first heard of the possibility of life in the southern hemisphere (denied by earlier scholars) in discussions in the Medici court in 1487.
That same year, Farissol took part in an intellectual exercise not without danger for a mediaeval Jew. In the court of the Duke of Ferrara, he debated with a Dominican theologian and a Franciscan friar, on the respective merits of Christianity and Judaism. We know about the debate because Farissol wrote about it in another manuscript, but frustratingly, says Dr Bolton, this grand setpiece was not recorded or commented on by Christian theologians.
Perhaps one of the most exciting things about Farissol is that - very unusually for a Jew of this period - he knew both Italian and Latin. "Occasionally," says Dr Bolton, "he makes a mistake. Iggeret is an attempt, from inside a library, and without travelling anywhere, to chart where all the Jews were in the world. So in this manuscript he writes about 'King Dog' in the Middle East. In fact he meant the Mongolian Khan, but instead of writing 'Khan' he wrote 'Can' - from canis, the Latin for dog. And from this one slip we know that he was aware of Latin."
The manuscript, which is estimated at £100,000-150,000, is on show to the public at Sotheby's for four days before the sale - from Friday July 6 to Monday July 8. It is the last version of a published book produced before widespread mechanical printing: and it raises a long-hidden curtain on the role of Jews in Renaissance Italy.