Cipher Bureau plot
"Busting an International Spy Ring!"
"The Cipher Bureau" is a part of the government agency designed to intercept and decipher secret messages and codes. Philip Waring heads the department and has to deal with a German spy band operating in Washington. Philip enlists his brother Paul, a naval officer, to find the exact location of the radio transmitter used by the spies. When Paul travels to Washington, he meets the attractive Therese Brahms who works for the spies. Philip, meanwhile, discovers that the spies want to get their hands on the plans for an improved version of the French 75mm weapon.