The Hypersonic Secret
by Dixon, Franklin W.
Series:Hardy Boys Mystery Stories
Prefer borrowing? Open Library may have a digital copy too.
AR Book Level
5.2
AR Points
5
Word Count
31,800
Interest Level
Middle Grades (MG 4-8)
Genre
Fiction
AR Quiz #
19735 EN
About this book
The boys investigate the disappearance of Mr. Hawkins when his plane drops out of sight over the mountains. Book #135.