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, 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 the brilliant white glare of the searchlight, the startling secret of the caves is dramatically revealed.
- ISBN10 0448089076
- ISBN13 9780448089072
- Publish Date 1 May 1929
- Publish Status Active
- Publish Country US
- Publisher Penguin Putnam Inc
- Imprint Grosset & Dunlap Inc.,U.S.
- Format Hardcover
- Pages 192
- Language English
- URL https://penguinrandomhouse.com/books/isbn/9780448089072