Frank and Joe Hardy embark on a thrilling underwater adventure to uncover a mystifying submarine responsible for mysterious disappearances in Barmet Bay.
Age
9-12
Text complexity
intermediate
Length
187 pages
Book in series
#17
Why to read
Exciting adventure story with suspense and mystery.
Teaches the values of teamwork, bravery, and problem-solving.
Encourages interest in history and marine investigation.
Classic Hardy Boys tale that introduces young readers to detective genre.
