The three exit ramps from the car park were rotated in irregular sequence, to make life harder for anyone trying to keep tabs on the movements of the staff of 46 Carlton House Terrace. The one in use tonight took me out into Cockspur Street, opposite Canada House. Whether they didn’t know there were any other ramps, or whether they knew which one was in use tonight, or whether they had all three covered, I did not find out, but I spotted them before the registration number of my car had even sunk into their brain cells – not that they could have learned a lot from it; the day after Gelignite had succeeded in cracking my private fortress, I had had the name and address of the owner of the Jaguar changed on the police files, and on the Swansea central vehicle registration files, to one Angus McTavish, who resided on a remote atoll thirty miles north-west off the coast of John o’Groats, Scotland’s most northern tip. McTavish did not exist, but the island did. Anyone else who had the bright idea of trying to track me down through my car licence number was in for one hell of a long journey, with little to show for their efforts, other than, perhaps, some snapshots of an uninhabitable rock covered in bird-shit.

The dark blue Marina crept up through the busy traffic in the Mall, and stuck two cars back from me; it stayed with me up St James’s, and down left into Piccadilly. There were still scorch marks on the tarmac from the previous week. The Marina forked left behind me into Hyde Park Corner, but still I couldn’t be one hundred per cent sure. I still couldn’t be completely sure as I went around and took the Park Lane turn-off, and held my speed to thirty, although the legal limit was forty. The Marina stayed back, letting other cars pass. There were two men in the Marina. Caucasians.

I turned sharply left, down the ramp to the filling station; they didn’t follow. If I was right and they were tailing me, they had just shown that I wasn’t dealing with complete amateurs. I stuck five pounds worth of petrol in the tank, which topped it to the brim, and drove out again. The Marina was circling Marble Arch.