The spying game

Some of us grew up worrying about reds under the bed, which was perhaps not as foolish as all that if a report on Saturday morning’s Today programme on Radio 4 is to be believed. Amid a cacophony of weird-sounding bleeps and disembodied voices, Gordon Corera, the BBC’s security correspondent (always clear, calm and collected, no matter the brief), told us about the ‘number stations’ that proliferated in the Cold War and are now being brought back to life. Anyone can tune in to them, but only those in the know can understand what they mean, and although the source of the transmissions can be traced it’s impossible to pick up those who are listening in to them, which is why they have come back into use. It’s so much safer a means of communication than email and mobile phones. No tracking possible.

These radio broadcasts are designed to be heard by spies, who have only to tune in to the designated frequency to pick up their next command simply by decoding the number sequence that’s being transmitted into the ether. Who the listeners are, where they are, cannot be established. The transmitters have been traced here, and in Virginia (a tool of the CIA), and they are very much back in use in North Korea. Their eerie, shivers-down-the-back quality emanates from that mysterious intangibility and yet their very real purpose. Also the fact that they can be heard in your living room, messages from the dark web of international espionage.

Corera took us to a house in south London where writer and researcher Lewis Bush has a battery of radios tuned in to these stations, listening live to coded messages from intelligence bureaus across the world. Bush picked up a British signal, nicknamed the Lincolnshire Poacher after its musical call sign (or alert system, indicating a message is about to be broadcast), which is based on the English folk tune.