Frank and Joe Hardy are determined to bring to justice the vicious criminals who kidnapped their detective father while he was investigating sabotage of a road-building project in the Kentucky wilderness.
After Mr. Hardy 's amazing escape, the boys pick up a clue - the word "Felix" mumbled by their sick father in his delirium. When they discover that the dossier of a notorious ex-convict has been stolen from Mr. Hardy's files, the two young sleuths are doubly spurred to action.
The trail leads them to New York City but ends abruptly in a cemetery! Stunned, Frank and Joe come upon another clue - a spiral symbol. Aided by their pals, the boys take jobs on the highway construction crew in Kentucky to try to track down the kidnappers and the nefarious saboteurs. But who among the crew is friend and who is foe?
In a desperate maneuver that almost costs them their lives, the Hardys bring to a spine-tingling close one of the most action-packed and suspenseful mysteries they have ever solved.
To prevent the criminals from finding out who the Hardys and their friends were, All 6 boys used alias last names.
- Frank Hardy - Frank Teller
- Joe Hardy - Joe Jensen (Blond hair allowed him to pass as Swedish)
- Chet Morton - Chet Ball (per the ball he had been working on
- Biff Hooper - Biff McGuire (due to his ruggedness)
- Tony Prito - Tony Gonzales (Olive skin-tone allowed him to pass as Mexican)
- Phil Cohen - Phil Rubinow
Businesses and organizations
- Prito Construction Company
to be added.
- ↑ Who Wrote the Hardy Boys? at Keeline.com
- ↑ The Mystery of the Spiral Bridge Major Edition Types at The Hardy Boys Unofficial Home Page
to be added.