This book recovers the lives of four men masked behind one legend. Reinterpreting recently rediscovered documents shows a Tuscan artist Leonardo da Vinci was banished from Florence around 1477, when at the same moment another Leonardo arrived from the East, an Ottoman agent from Genoese Caffa in the Black Sea. This Leonardo was a military engineer, who began writing technical notes backward in a flourishing Italian script. In Florence, around 1500, he met the alchemist and polymath Zoroastro, who collaborated in producing the scientific Notebooks. However, by the mid-sixteenth century, all memory of Zoroastro had been erased, and the two Leonardos had been conflated into one identity. Crucially, an archived document, rediscovered around 2021, proved that the Tuscan painter Leonardo da Vinci died in 1499. This information leads to the recovery of the artist who really painted the Mona Lisa, Giovanni Antonio Boltraffio.