The Radio Boys on Secret Service Duty

A group of curious teens—Bob, Jack and Frank—find themselves thrust from the quiet of a Long Island estate onto a Pullman carriage bound for San Francisco. When an enigmatic mountain man named Ed Harlan slips into their compartment, he hints at a secret plot that could threaten the West Coast, and the boys realize their next adventure will be more than another rescue. Their passion for the fledgling technology of radio telephony, sparked by their friend Jack’s scientific mentor, becomes the key to listening in on whispers that ordinary ears can’t catch.

As the youngsters settle into the bustling port city, they are soon recruited by a shadowy agency to act as junior operatives on a clandestine mission. With a homemade sound detector and a daring spirit, they navigate hidden docks, smokey taverns and the tangled web of smugglers and spies. Along the way they uncover cryptic signals, daring chases, and a looming danger that forces the Radio Boys to prove that youthful ingenuity can match even the most seasoned secret‑service agents.