Voir Leonardo, Series 1 - Episode 12

Leo and Lisa are summoned to the Medici Palace to undertake a special commission. Since they've stolen back Leo's notebook and Piero knows Lisa's a girl, they fear the worst. Piero is charming and explains that he wants Leo to join forces with him for the good of Florence and, when he discovers that Piero has had all his designs built, Leo is completely taken in. But it turns out that Piero intends using one of Leo's inventions to assassinate the Duke and now it's Leo's word against a Medici - in a matter of life or death.