Having found Caterina, Leonardo continues his work, but is frustrated by the growing success of a younger artist, Michelangelo Buonarroti. Putting his feelings aside, Leonardo allows himself to be persuaded to accept a new commission.

With time running out, Stefano races to save Leonardo and finally discovers the truth behind his biggest kept secret; armed with the facts but lacking the evidence, an unexpected revelation leaves Stefano turning to an unlikely source for help.