The Happy Hollisters and the Castle Rock Mystery (The Happy Hollisters, Book 23)
New York: Doubleday, 1963. Hamilton, Helen S. Hard Cover.
Top edge of jacket lightly rubbed.
174 pp. #23 in series. An abandoned rock quarry, mysterious flying objects, and a valuable deposit of titanium lead the five Hollister children -- Pete, Pam, Ricky, Holly, and Sue -- into their latest thrilling.....