I heard a strange warbling sound coming from a rarely-used part of the shortwave spectrum. Intrigued, I took down the time and frequency of the signal, then threw a tape into the cassette deck, recording it. After about ten minutes I figured that the signal was not going to change, so I ejected the tape and transferred the contents to my computer. Upon closer examination, it was a simple click that recurred approximately fifteen times a second and change.

I gave Withers a call. He’d done clandestine work for the US government during the Cold War and knew his stuff about radio. He informed me that he had heard a similar signal before, from something that NATO called Steel Yard, the rest of the Western world called the Russian Woodpecker, and the Soviets called Duga-3. It was an over-the-horizon radar system that disrupted radio broadcasts the world over, generating numerous complaints.

I asked if he would find its direction, as I would. He agreed. Now we just needed a third party and we’d have its source.