The Thing from the Soviet Union: The Great Seal Bug

No, it isn’t the name of a movie, but rather an interesting event in the early Cold War. Let me take you to the 4th August 1945, three months after the surrender of Germany, two days before the atomic bombing of Hiroshima, and eleven days before the surrender of Japan and the end of WWII. American ambassador W. Averell Harriman is given a carved wooden copy of the US Great Seal by some Soviet Young Pioneer Organization of the Soviet Union children as a gift of peace and friendship following the war. The Seal was then hung in the ambassador’s residence in Moscow for seven years before the secret listening device was discovered in 1951.

Figure 1: A replica of the seal in the National Cryptologic Museum. (Wikimedia Commons, 2026).

So what is “The Thing?” Well it’s a small listening device (or “bug”) that was located under the beak of the eagle, 23cm long and essentially a round “can” on a long metal stick which was the antenna. The magical thing about it was that it was unpowered and had no electronics in it at all, which was part of the reason it remained undiscovered for so long. The copper “can” had various grooves in it to conduct air and it was powered by external sources when the Soviets beamed transmissions externally to power it. When people talked, the membrane over the “can” would vibrate against a mushroom-shaped tuning post and act as a microphone. The grooves would reduce the stress on the membrane and the conversation was then transmitted via the antenna. “The Thing” weighed just 31 grams.

Figure 2: "The Thing" inside the replica Great Seal. (Wikimedia Commons, 2026).

How was it discovered? Well, in typical American fashion it required a British radio operator to notice something was amiss. The radio operator in the British embassy noticed American conversations occurring on an open Soviet Air Force radio channel whilst the Soviets were transmitting radio waves to the ambassador’s office to get “The Thing” to work. A State Department employee was then able to replicate this with a simpler method, provoking two more State Department employees, John W. Ford and Joseph Bezjian, to be sent in to investigate bugs in the US, British, and Canadian embassies.

Using a signal generator to create feedback from potential bugs, they swept rooms until Joseph discovered “The Thing” in the Great Seal. Various US and British intelligence agencies, including the CIA and MI5, analysed the device and were eventually able to figure out how it worked. Also in typical American fashion, the membrane was damaged during handling and had to be replaced.

The results of this was that the British soon developed their own version of “The Thing” which was called SATYR, and it became used by the Commonwealth of Nations and the Americans, while development of this technology was continued by the Americans until the late 1960s when passive listening devices like “The Thing” fell out of favour due to superior, active listening devices becoming more viable. It was finally mentioned by the UN Security Council in 1960 when it was brought out as a counter argument to the Soviet protest at western spying, following the U2 spy plane incident that year after the Soviets shot down the plane over Russia. “The Thing” was used as evidence that both sides on the Cold War were spying on each other mutually.

The replica of “The Thing” and the Great Seal was made in 2025 by John Little, a 79 year-old-man who made a functional replica of it. It was the subject of a documentary and now sits in the National Cryptologic Museum in Maryland, USA.

Berengar Needham is currently a student on the MA Museum Studies program at the University of Leicester.