C.R.O.P.: Covert Rural Observation Posts are places where men like Danny 'Badger' Baxter hide for endless, motionless hours, secretly recording criminal or terrorist activity.
But now Badger has a bigger job than photographing dissident Republicans in muddy Ulster fields or Islamic extremists on rainswept Yorkshire moors.
I.E.D.: Improvised Explosive Devices are the roadside bombs which account for 80% of British casualties in Iraq and Afghanistan.
MI6 have a plan to assassinate the leading maker of these weapons when he leaves his house in Iran to visit Europe. But first, they need to know when he is leaving, and where he is going.
So it is that Badger finds himself on the wrong side of the Iranian border, lumbered with a partner he loathes, lying under a merciless sun in a mosquito-infested marsh, observing the house. And knowing that if they are caught, Her Majesty's Government will deny all knowledge of them.