Milan, 1506. Leonardo da Vinci is arrested for poisoning Caterina de Cremona. After protesting his innocence to Stefano Giraldi, Leonardo remembers back to his days as an apprentice in Andrea del Verrocchio’s studio, where he first meets Caterina. As their relationship becomes one of some complications, Leonardo faces major hurdles in achieving success with his work, until Verrocchio asks him to help him with the commission of the Baptism of Christ.