For such a covert plan, Operation Acoustic Kitty is a pleasingly literal and Austin Powersish name. During the 1960s the Americans had obviously bugged all the Soviet embassies, but in spy circles bugging is a little like a vote of no confidence in the South African parliament: it would be weird if you didn’t do it, but no one seriously expects it to produce results. The hitech Soviet technique for avoiding the bugs was to walk outside and conduct their conspiratorial commie conversations in a public park, with newspapers covering their mouths so no one could read their lips.

This was frustrating for the Americans, but it also made them think. What is so common in public parks as to be perfectly inconspicuous, but might be used to conceal a listening device? For me the obvious answer is a pigeon or a drug dealer, but for the CIA it was a cat. Russians are notorious cat-lovers, and surely even a beady-eyed Bolshevik wouldn’t look twice at some bored tabby slinking past. Cats are famously tricky to train, so who would suspect them?

The problem with this, of course, is that cats are famously tricky to train. The CIA had a solution.

The first step was to open up a cat. They chose a young male named Peanut. The second step was to implant a battery pack in Peanut’s abdomen, to power the listening device they implanted in his cochlea. The next steps are where it becomes more weirdly 1960s spymovie-ish. They attached electrodes through which they could use a remote control to give Peanut electric jolts to steer him from afar. Small pulses would get him walking; a pulse on the right would make him turn left; there was some way to make him stop. Peanut became a purring guided microphone.