The Hardys begin helping their father on two mysteries simultaneously, the first relating to sabotage at a new radar station near Bayport, the second, the mystery of a teacher who has disappeared from nearby Kenworthy College. Before long the trail has lead to Rockaway and the mysterious events at Honeycomb Caves where the brothers join their friends Chet Morton and Biff Hooper on a camping trip. And it's there that things really start to heat up.
Once again, the Hardys' unchallenged status as a pair of danger magnets gets them and their close friends into trouble. Car crashes, booby-traps, the boys are even tied to the train tracks at one point. This is another dose of full-on action and it's great fun. It never strays too far from the standard formula so it's not exactly a stand-out volume in the series but that's okay because the formula works and it's well-applied and the whole thing is well written. ( )

Triggered by the disappearance of a brilliant young professor, this mystery takes the Hardy boys first to Kenworthy College, where they find a puzzling message on an examination paper. But then their pal Chet Morton, with his new metal; detector, and buddy Biff Hooper, turn up a clue that sends the young detectives on an exciting search in another direction—to the Honeycomb Cave, on the seacoast. A hot-tempered hermit who considers the caves his private domain complicates this seacoast mystery and challenges every sleuthing skill Frank and Joe possess.
The case that their famous detective father is working on suspected sabotage at the new radar station near the Hardy’s home town of Bayport further complicates the mystery, which grows more baffling with every chapter.
After many dangerous encounters, including a nearly disasters patrol on the stormy ocean, Frank and Joe discover a powerful searchlight in one of the craggy caverns along the seacoast. In the brilliant white glare of the searchlight, the startling secret of the caves is dramatically revealed. ( )

http://benfulton.net/blog/2005/09/boo... ( )