Leonardo and his allies are forced to retreat when the Ottoman Empire storms the city of Otranto.

Leonardo and friends have to help survivors escape the city. Vanessa must help the Signori decide the fate of Florence. Pope Sixtus continues to raise an army for his Crusade. Clarice continues her search for Carlo.

Leonardo investigates a horrific murder that may result in the Labyrinth being exposed.

Carlos's attempt to program Leonardo into becoming one with the Labyrinth leads him to slip into an alternate reality that could prove life-threatening.

A paranoid Leonardo becomes shut off from his friends, while an endangered Lucrezia searches for a way to make amends for past sins.

Riario fights his own inner demons. Leonardo is struggling with his conciousness - is he an enlightened inventor or just an inventor of weapons of mass destruction? Lucrezia has found out the inconvenient truth about her former ally.

Cities are falling to form the Crusade and Leonardo is seeking for the solution to reverse it. Lorenzo is back but heavy experience really changed him to become a tyrant.

While Nico and Zo seek out support for the Crusade from an old foe, Leo is ambushed by the Labyrinth.

Leo and Sophia struggle to control the mysterious device they've built. Back in Florence, Riario awaits judgment while Lorenzo and Vanessa take their partnership to the next level.

Following the Ottoman army's ambush on Crusage forces, Leo must put his faith in his friends and in himself if they're to have a chance to defeat the Turks.