Operator #5

Operator #5, America's Secret Service Ace, appeared in 48 novels in the classic pulp magazine bearing his name. From April 1934 to November 1939, Jimmy Christopher fought villains from inside the United States and invaders from without.
With World War II looming on the horizon, the Operator #5 novels became a reflection of the times, showcasing American fears of technology and oppression.

"The Masked Invasion" is the first entry in the series. Jimmy Christopher, Operator #5 in the American Intelligence Service, faces off agasint the Masked Empire, an organization that threatens the very existance of the United States with a super-weapon capable of plunging an entire region into total darkness -- with no ability to use electrical machinery!