A talented young pavement artist named Tomaso turns up looking for an apprenticeship at the workshop of the artist Verrochio, where Leonardo is already an apprentice.

Lorenzo's father Piero de' Medici masterminds the theft of Leo's notebook. However, it proves to be no use to him because all the formulas and calculations are written in code.

Leonardo has been working on a massive pair of wings, with which he believes he's going to be able to fly. Convinced he'll die in the attempt, Tomaso does everything possible to stop him, but, Leo is determined and certain that the wings will work.

Leo and Tom are commissioned to paint the wedding portrait of Petronella who is engaged to the evil loan shark Lucio. Petronella is sacrificing her own happiness to save her father, who is heavily in debt to Lucio.

Tom is really a girl called Lisa, who has chosen to live as a boy to fulfil her ambition to paint. Hanging out in all-male company can be a strain, especially when Leo never notices her and instead falls in love with Lorenzo's cousin Valentina.

Lorenzo smuggles Leo into the palace to show him an extraordinary object - a plain box, which produces an amazing light show. Leo creates a replica and they swap the boxes so Leo can discover how the original works.