The Secret of the Caves
The Hardys and their friends discover the key to a spy ring while exploring a local cave.
Reviewed on 8th November 2014
The seventh book in the original Hardy Boys series (actually, my copy is the Anglicised version of the 1964 rewrite) depicts the brother detectives helping their dad in another case and going hunting for treasure with their friend's new metal detector.
Although the plot feels quite coincidental in its structure, by this point the stories seem to be moulding themselves into more of a traditional detective story structure and the two boys are becoming more independent.
I enjoyed this mystery for the most part, although I thought it was very clear where some of the story had been dramatically updated for the 1960s version and probably didn't match the original.