This not unexpected blast of avant-garde jazz-rock happened around half twelvish. It was the signal. Our presence was required at an anonymous car-park not far from the border between Cornwall and England.
We sprang into action, ignoring the plaintive mewls from assorted moggies questing after lunch. Or second breakfast. Or some fussing. Or all three.
Soon the little pink car substitute that we use for incognito transport was shimmering along the road through Crafthole and onward past Sconner to our long awaited assignation.
Our contact was already in place as we arrived; our only way of recognition was a long-range telephoto lens shot. But we knew her immediately.
And so the deal was swiftly completed, before any passing motorist might find themselves unwitting witness to the handover.
The parcel was delivered into our hands and we can pass on to the world the news that the "eagle has landed".