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

Leo devises an escape from Otranto but may not be able to save those closest to him.

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

Carlo'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.

A former nemesis returns to Florence and stands in opposition to Crusade efforts. Vanessa and Nico ponder their futures; Leo attempts to decipher the Turkish armor.

Nico and Zoroastre turn to an old enemy to gain support for the Crusade. 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.

Leo must put his faith in his friends and in himself to have a chance to defeat the Turks.