I got the M4 in my shoulder, laser on. The rest of the cave was clear. The blast had been a flash-bang, not frag. Pound to a penny they’d try and gas me out. I pulled the respirator off his face and on to mine and then I scraped a heap of bones over his rifle’s flashlight. The ossuary went darker, but not black. The lip of the arch under which we’d first entered the room threw a shadow back towards me. Then the whole edge of the roughly hewn doorway juddered as more light fell on it. It was being lit from the other side. I knelt and squinted down the passageway. Torches, not carbide lamps. Half a dozen of them, closing in.

French GIGN assault team or Russian death squad? The motopsycho nightmare ride across the capital had floored a lot of policemen – but none had died by my hand. I intended to keep it that way for as long as possible. Fifteen metres. I took the sting-ball grenade out of my jacket pocket, and stepped back from the low archway. Ten metres. I pulled the pin, let the lever fly clear, and flung the little black ball down the passageway.

A loud bang. Exploding rubber and CS gas. I heard a man fall. One screamed. They all stopped. I backed away, M4 up, facing the gateway, treading the hill of bones in reverse back to the escape hole. I imagined my shoulders grinding bone against bone as I tried to work my way up again. But there was no time to get clear.

The men in the tunnel were already up and running, boots pounding on the passage floor. I squatted down, the stock of the damaged rifle braced to my right hip by my right elbow. In the half-dark I hooked the index and middle fingers of my left hand around the T-bar of the M4’s charging handle. A metal cylinder bounded through the archway, billowing white smoke. CS gas, most likely. Then another. There was a pause as the room filled with vapour, and then the first man came in at a crouch. I landed my red dot on the shooter’s left shoulder and followed it with a single 5.56 round. I was glad of the suppressor.