"Do not follow various and strange sophisticated doctrines that spread pestiferous seed", wrote Clement VI himself in 1436 to the teachers and students of the University of Paris. The Pontiff, in that letter, referred to the doctrines of an illustrious Franciscan monk of English origin named William of Occam, who had fled several years before from the Avignon jails accused of heresy. For four years he had been held, until he managed to escape and request asylum at the court of Emperor Louis of Bavaria, at that time at odds with Pope John XXIII. When the Emperor died, William wanted to return to union with his order and with his Church, which is why he traveled to Italy accompanied by his young novice to meet with Bernodo Gui, then head of the Inquisition in that area and representative, ultimately, of the Pontiff. However, it is not known with certainty whether Gullermo actually achieved his goal. Only the testimony left by his disciple, many years later, in a collection of scrolls; where the astonishing and terrible events that happened during the week they stayed at the Abbey are related, that appointment had been scheduled. The testimony of history that you are now going to relive ...