00840cam a2200229 4500 360723116 TxAuBib 20081022120000.0 850822s1968||||||||||||||||||||||||eng|u 68021715 DLC DLC ICrlF TxAuBib Keene, Carolyn. The clue of the black keys. New York : Grosset & Dunlap, [1968] 174 p : illus ; 20 cm. Her Nancy Drew mystery stories ; 28 Once again Nancy Drew is involved in a mystery as she tries to locate an archaeologist who disappeared with the clues to a buried treasure. 6.5 Dale-Chall Formula. 20081022. Mystery and detective stories. Her Nancy Drew mystery stories ; 28.