Sleight of Dan
Nancy and the girls see a stage magician perform and Nancy is, of course, noting how the tricks are done. One trick goes awry when the female assistant actually disappears.
Nancy knows that the magician and his assistant have argued so she checks things out and nearly gets eaten by a huge snake. The story revolves around the magician's relationship to the assistant and there's no actual crime here. Overall, it's the weakest story in the manga series so far.