Italy prepares itself for an attack from the Ottomans. Riario is been stalked by danger. Nico is the only person who can control what happens to Vanessa.

Leonardo returns to a changed Florence - not all is as it seems. What will become of a changed Riario?

As Leonardo and Riario prepare to die, Zoroaster and Nico plan their escape. Meanwhile, Lorenzo tries to meet with the king of Naples and Bayezid visits Rome.

Clarice's life is in danger. The fellowship enters the Vault of Heaven, which holds many mysteries and deceptions. Lucrezia reaches her destination, meeting someone along the way.

Lorenzo fights for survival. Leonardo finds out new secrets by going into the Door of Heaven.

Leonardo reunites with Riario and Nico in the New World. Lorenzo attempts to save Florence with the help of an old flame. Clarice struggles to retain control of the Medici Bank.

Leonardo and Riario find that entering the Vault of Heaven is not as easy as they may have hoped. Meanwhile, Lorenzo becomes embroiled in Ferrante's games and Lucrezia meets the Turk.

Pope Sixtus excommunicates Florence. Lucrezia comes up with a plan to see her imprisoned father. Da Vinci tries to take Duke Alfonso's ship.

Lorenzo manages to get back to the palace with the help of Da Vinci. Riario whereas continues on the voyage. The Pazzis are hanged for their conspiracy.

Leonardo and Lorenzo struggle to escape Riario's forces as Florence falls into chaos.

The Pazzis plan to overthrow the Medicis on Easter. The Turk tells Leonardo the location of the Book of Leaves. Later, Lucrezia admits a startling secrect, and Leonardo saves the Medicis.

Leonardo builds an underwater suit and breaks into the Vatican through the sewer. He meets the Pope and the mysterious prisoner. Giuliano reveals the identity of spy in Rome.

The Turk's clue about the Book of Leaves leads Leonardo to encounter Vlad Dracula, while Lorenzo and Piero meet with the Duke of Urbino. Later, the search for the Medici's spy intensifies.

Piero, Leonardo's estranged father, is ordered to defend his son in court. Later, Leonardo turns a corrupt judge during a performance for visiting royals. The Turk makes an appearance.

Bechhi is accused of spying for Rome and arrested; Leonardo unveils his latest weapon; Florence's army squares off with Rome's. At a party in his honor, Leonardo is arrested for sodomy.

Riario discusses his defeat with the Pope and a mysterious prisoner, while Leonardo searches for a rational explanation to an outbreak of demonic possessions that is blamed on the Medicis.

Leonardo's quest for the Book of Leaves continues, and his failing war designs for the Medicis cause a rift between them. A papal spy, Riario, is defeated by Leonardo and returns to Rome.

Da Vinci is commissioned by the Medicis to create an Easter spectacle in Florence. Later, he's hired to build war machines, and meets a mysterious Turk.