In the early 1920s, nearly blind physics prodigy Mourly Vold finds out how to tap into the nation's long distance telephone lines. With the help of Alexander Graham Bell, Vold tries to warn the phone companies that would-be saboteurs could do the same thing, but they ignore him. Unfortunately, his taps do catch the notice of William Randolph Hearst, who hires Thomas Edison to get to the bottom of them—and the chase is on!