There's something very strange happening in and around Bayport and the Hardy Boys are doing their best to get to the bottom of it.It's all triggered by the disappearance of a brilliant young professor. The mystery takes the boys first to Kenworthy College where they find a puzzling message on an examination paper. But then, a new clue is unearthed that sends the young detectives to the Honeycomb Caves. After many dangerous encounters, Frank and Joe discover a powerful searchlight in one of the craggy caverns along the seacoast. In its brilliant white glare, the startling secret of the caves is dramatically revealed.
