Series
Genres
Publication
Grosset & Dunlap (1929), 180 pages
Description
As Frank and Joe investigate the mysterious disappearance of a college professor, they stumble upon a baffling secret in a complex network of caves.
Lexile
700L
Original language
English
Original publication date
1929
1965 (revised)
Subjects
Physical description
180 p.; 5 inches
ISBN
0448089076 / 9780448089072