In 1497 a Dominican inquisitor is sent to Milan to supervise the final phase of the painting of The Last Supper by Leonardo da Vinci. Never a conformist, da Vinci creates a masterpiece that raises questions that have yet to be answered. Unlike his contemporaries, he does not hold strictly to the religious doctrine of the scriptures, but adds touches advocated by a repressed heritical sect. Could da Vinci be a member of the secret society?