When Leonardo da Vinci is commissioned to paint 'The Last Supper' , he believes it will seal his reputation as the finest artist in Italy.

Yet all does not go as planned. The notorious Papal emissary, Father Rodrigo of Salamanca accuses him of blasphemy over his decision to choose a lowly peasant, Alessandro, to be his model for Jesus.

To Leonardo's horror, Alessandro takes on quasi-religious significance for the populace of Milan, dragging both into a journey of political and religious upheaval, violence and scandal, which eventually leads to their climactic confrontation.