When the four friends receive a strange sketch, their lives change abruptly. They start an investigation because they want to know where exactly the sketch came from. When they realize that they are on to a big secret which ends up in dangerous situations. They steal an old manuscript in Paris, they participate in an ancient game and have to carry a body through Florence without getting caught. There is no time to lose. Risking their own lives they continue their search. Will they ever learn the truth about the biggest secret ever: The Lost Leonardo?