A simple groom nicknamed Dino, who was also an apprentice of the great Leonardo da Vinci, was afraid to even remember the bloody events that took place in the Lombard castle of Duke Sforza, the reigning Duke of Milan. At the insistence of the great Leonardo, Dino from a young apprentice turned into a beautiful maid serving the young contessa - the daughter of the almighty Duke, where he became the eyes and ears of the master. He was tasked with studying the situation in order to find out the name of the killer who was taking the lives of commoner women. But this righteous deed gave rise to another wave of mysterious crimes. Moreover, Leonardo and Dino witnessed the death of people, miraculously avoiding their own death...