Nancy, Ned, and George attend magician Dan Devil's show, and witness his assistant's magical disappearance—except she doesn't reappear! Seems Nancy can't even go on a date without stumbling upon a mystery. In searching for the missing assistant, Nancy goes on a magical mystery tour of Dan Evil's home and runs into a very hungry anaconda! Rather than become snake food, she agrees to become Dan's new assistant—but what if she vanishes too?