“The Walls Have Ears: The Greatest Intelligence Operation of World War II,” by Helen Fry, Yale University Press, 2019, 320 pages, $26
When World War II started, British Intelligence embarked on one of the war’s most audacious information-gathering projects.
They outfitted cells in the Tower of London for prisoners of war to secretly eavesdrop on inhabitants’ conversations.
“The Walls Have Ears: The Greatest Intelligence Operation of World War II” by Helen Fry, tells what happened.
The rooms were fitted with hidden microphones, some outside the building near openable windows. These caught conversations by POWs leaning out the window to avoid microphones possibly planted in their rooms. The conversations were recorded and later translated by German-speaking operatives.
The POWs in these cells were subject to clumsy intelligence interrogations by seemingly inept interrogators. Returning to their cells afterward they often bragged about outsmarting their questioners to others in their room, revealing the secrets sought during the interrogation. Other times, gossip revealed invaluable intelligence nuggets.
The Tower of London operation proved so successful it was replicated in three other places, most notably at Trent House, a stately country house in North London.
This housed captured German generals. They were housed in comfortable quarters, provided luxuries and would be greeted by “Lord Aberfeldy,” a fascist-sympathizing Scots peer (actually an untitled Scots actor). The generals frequently forgot they were POWs and spoke freely about their experiences.
The operation revealed secrets of German nighttime air navigation technology. This enabled British scientists to bend the radio beams directing German night bombers. Their bombs fell on open fields — not the targeted British cities.
It provided advanced warning of the V-1 and V-2 projects, leading to attacks, which delayed both. It also provided early and accurate information on the Holocaust. Combined with operational intelligence gathered, this operation gave the Allies the edge needed to defeat Germany.
The project involved hundreds, many anti-Nazi German nationals providing translation services. It was kept highly secret during the war, and decades afterward. (Secrecy permitted reuse in a potential future war with the Soviets.) Those participating maintained that secrecy until the British declassified it in 1999.
“The Walls Have Ears” is a fascinating and intriguing book about a decisive yet unknown World War II intelligence operation.