R.H. Tandy illustrated Nancy spying on the criminals in the original cover art, along with a frontispiece and three internal illustrations showing various elements of the story. He updated the frontispiece in 1943. In 1950, the dust jacket art was changed to show an updated version of Nancy with the crooks behind her. This art was not retained for the story revision in 1961, as the scene is eliminated by a completely different story. Rudy Nappi illustrates a ghostly picture of two girls illuminated by glowing lights in the cuff of their long-sleeved gowns. (The 1961 cover art appears to feature both Nancy, facing, and a mysterious dark-haired girl. In actuality, Nancy has her back to the reader, and is the dark-haired girl in the foreground; the other girl is actually Nancy's impostor.)