After the deaths of two female servants, Leonardo da Vinci asks his apprentice, Dino, to go undercover disguised as a woman in the service of the Duke's ward. The task should prove easy since "Dino" is in reality Delfina, a young woman masquerading as a boy to serve as Leonardo's apprentice. But complications in the case soon have the young apprentice torn between her loyalty to Leonardo and her growing feelings for a captain of the Duke's guard.