A youthful Leonardo da Vinci studies art under his master, Verrochio in Florence, Italy in 1473. While working as an apprentice under Andrea del Verrocchio, Leonardo learns about color, shading, sculpturing, panel painting and painting of altarpieces. Self-discipline is the key to success in Verrochio's opinion. In 1498, Leonardo is under the service of the Duke and Duchess of Milan. He is commissioned to sculpt a statue of the Duke's father and paint " The Last Supper" for the monks in their dining hall. The Duchess of Milan asks Leonardo to produce a play about stars, planets and space. He is obviously not excited about the project because of the time it will take away from his masterpieces. During the play, Leonardo sees a young boy, Salai, steal some money from the stagehands. Salai tells Leonardo that he is homeless and hopes to become an artist like Leonardo some day. Leonardo invites Salai to live with him and tells him that he will teach him how to paint. The city of Milan erupts into fire while at war. Salai and Leonardo escape with all his sketches and return to Milan. Milan is different from what Leonardo remembers. The apprentice school is no longer being used. Leonardo meets a young Michelangelo. It becomes apparent that Michelangelo and Leonardo's thoughts about training in the arts are very different. Passion and creativity versus discipline and rules. Salai becomes reckless and rebellious. Leonardo strives to keep Salai on the path of righteousness. While trying to develop a method to conserve wall paintings, one of Leonardo's paintings begins to melt off the wall. Leonardo is discouraged and decides to return to Milan. Salai decides to stay in Florence with Michelangelo. Leonardo leaves feeling like a failure. Upon his return to Milan, he visits his painting, "The Last Supper," and sees that young apprentices are using his painting as their study. The young apprentices ask to shake the master's hand, Leonardo da Vinci's hand.