A talented young pavement artist, Tomaso, turns up looking for an apprenticeship at the workshop of the artist Verrochio, where Leonardo is already an apprentice. Leonardo has seen Tomaso's work in the streets and encourages Verrochio to take him on. Then the gang catch Tomaso trying to steal Leonardo's priceless notebook, containing all the diagrams and plans for his inventions. Tomaso is not what he seems and the gang's hostility soon turns to amazement when the truth comes out. Though none of them can guess the real story - not even Tomaso.