Nancy meets the Fontaine's, refugees from the fictional country of Centrovia, who run a dancing school in River Heights. The Fontaine's receive threats from a mysterious assailant and Nancy offers to help, but then the Fontaine's disappear. Nancy begins her search for them and becomes involved in a mystery involving a pair of scarlet dancing slippers, a painting, and missing jewels. There are many people pretending to be friends of the Fontaines, but Nancy does not know if they are lying. Come, follow Nancy during this dangerous quest by reading the book, "The Scarlet Slipper Mystery".