The Radio Boys on Secret Service Duty

The Radio Boys on Secret Service Duty by Gerald Breckenridge, author of
“The Radio Boys on the Mexican Border,” “The Radio Boys with the Revenue Guards,” “The Radio Boys’ Search for the Inca’s Treasure,” “The Radio Boys Rescue the Lost Alaska Expedition.”

CONTENTS
Chapter 1. Frank “Listens In”
Chapter 2. Loose Ends of a Plot
Chapter 3. The Man of Mystery Again
Chapter 4. Enter Inspector Burton
Chapter 5. The Sound Detector
Chapter 6. In the Enemy’s Toils
Chapter 7. A Break for Liberty
Chapter 8. Chinatown Wins
Chapter 9. The Power of the Underworld
Chapter 10. Carried Captive to Sea
Chapter 11. “Best Laid Plans”
Chapter 12. A Storm at Sea
Chapter 13. Hope Is “In the Air”
Chapter 14. The Upper Hand Regained
Chapter 15. Abandon Ship
Chapter 16. Doctor Marley Explains
Chapter 17. Lost Trail
Chapter 18. Closing in
Chapter 19. The Sound Detector Detects
Chapter 20. In at the Death
Chapter 21. At Santa Cruz Island
Chapter 22. In the Smugglers’ Cove
Chapter 23. A Signal from the Radio Station
Chapter 24. A Spy Captured
Chapter 25. A Forlorn Hope
Chapter 26. A Surprise Attack
Chapter 27. Black George Captured
Chapter 28. Rewards Ahead
Chapter 29. A Look into the Future