[NANCY DREW MYSTERIES]. KEENE, Carolyn. The Secret of the Old Clock. New York: Grosset and Dunlap, [ca 1931].8vo. 10-page publisher's advertisements at end. 4 black and white plates by Russell H. Tandy. Original blue cloth, lettered in orange on front cover, lettered in black on spine (very light wear along edges); pictorial dust jacket (some chipping and short tears, small stain on rear panel.An early edition of the first Nancy Drew mystery with no silhouette on the front cover, plain endpapers, no silhouette on the white spine panel of the dust jacket, and with the listing of additional children's book series on the inside of the dust jacket. The front flap of the dust jacket advertises the 6th book in the series The Secret of Shadow Ranch. An early example of this enduring young adult classic series.