Three American middle school students are not going to be taken in when, on a school trip to Florence, Italy, they meet a man claiming to be Leonardo da Vinci, back from the dead. This imposter claims to have a mission to better humankind, and, remarkably, it seems plausible. Gina, Max, and Tad decide to assist this man, who just may be Leonardo in truth, and learn a lot about modern science, history, math, and art along the way.