Rising artisan Leonardo da Vinci is commissioned by the powerful Medicis to create an Easter spectacle in Florence, after some maneuvering, da Vinci is hired to engineer war machines and a mysterious Turk intrigues Leonardo.

Leonardo continues his quest for the Book of Leaves, the Pope's nephew arrives and meets his spy, Leonardo's war designs fail, causing a rift with the Medicis and the Pope learns of Leonardo's prowess.

Riario discusses his defeat with the Pope and a mysterious prisoner; an outbreak of demonic possession at a convent is blamed on the Medici's, but Leonardo searches for a rational explanation.

Becchi is arrested and accused of being a spy for Rome. Meanwhile, the armies of Rome and Florence face off and Leonardo reveals his latest weapon.

Lorenzo orders Piero da Vinci to defend his estranged son in court. Meanwhile, the Turk visits Leonardo at his workshop.

The Turk's clue regarding the Book of Leaves leads Leonardo to Wallachia, where he meets Vlad Dracula. Meanwhile, the hunt for the true spy continues.