Packed with suspense, action, and clever sleuthing, The Secret of the Caves is a classic Hardy Boys adventure perfect for young detectives and mystery lovers alike.When the Hardy boys set out to investigate the strange disappearance of a college professor, the trail leads them to Honeycomb Caves--a labyrinth of danger and intrigue hidden along the coast. As Frank and Joe dig deeper, they uncover a web of mystery involving secret radio signals, suspicious strangers, and a threat that could shake national security.