Nancy witnesses a purse snatching and chases the thief. She rescues the purse, but not its contents. The owner, a doll collector, asks Nancy to do some detecting. The woman provides a mysterious note: "The source of light will heal all ills, but a curse will follow him who takes it from the gypsies." Nancy interprets this clue in her quest to find an old album, a lost doll, and a missing gypsy violinist. The girl detective’s valiant efforts bring happiness to a misunderstood child and her lonely grandmother. This book is the revised text. The plot of the original story (©1947) is similar with one major and other minor revisions.