Chatter starts out at Menwith Hill, a secret eavesdropping station covered in mysterious, gargantuan golf balls, in England's Yorkshire moors. From there, the narrative moves quickly to another American spy station hidden in the Australian outback; from the intelligence bureaucracy in Washington to the European Parliament in Brussels; from an abandoned National Security Agency base in the mountains of North Carolina to the remote Indian Ocean island of Diego Garcia.

As Keefe chases down the truth of contemporary surveillance by intelligence agencies, he unearths reams of little-known information and introduces us to a rogue's gallery of unforgettable characters. We meet a former British eavesdropper who now listens in on the United States Air Force for sport; an intelligence translator who risked prison to reveal an American operation to spy on the United Nations Security Council; a former member of the Senate committee on intelligence who says that oversight is so bad, a lot of senators only sit on the committee for the travel.