No one knows for sure what is being heard when tuned into radio frequency 4625 kHz. Secret, coded messages sent across airwaves between governments and spies? A signal ready to sound an alarm? Or a mysterious transmission tuned to interact with the ionosphere? Known to be of Russian origin, though this has never been confirmed by the Russian government, the signal was a continuous broadcast of repeated pip that has since become an unsettling looping and buzzing tone.
For decades, the source of the broadcast was entirely unknown, until suddenly and unexpectedly, the first spoken words on the station identified it as UVB-76, broadcast from a military bunker in Povarovo, a small town 19 miles outside of Moscow. This interruption was soon followed by new strange and unsettling additions: rustling of someone moving around nearby, a harsh voice reading a series of names and numbers, and faintly eerie music playing in the background…