O título é Magia Negra e Azul por Zilpha Keatley Snyder
"You'd think that someone with a name like Harry Houdini Marco would be deft and skillful, but Harry could only occasionally catch even an easy fly ball without making some dumb error. On top of that, most of his friends' families were moving to the suburbs. It would have been a long, dreary summer, but then a Mr. Mazeeck showed up and turned out to be more than he seemed."
