I drove around Marble Arch and headed back down Park Lane, sticking to the inside lane. The Marina came down, three cars back, also in the inside lane. No one but an idiot, or someone wanting to turn left, drives down the inside lane of this part of Park Lane. We crossed the Brook Street lights, then on down, past the Dorchester lights, still in the left lane, the Marina two cars back now. The traffic was thick ahead and to the right of me; then there was a gap. I cursed the side-screens of the Jag, wishing that at this moment I had glass windows with clearer vision. I looked out; there was a truck coming down fast. I slammed the gear-lever into first, flattened the accelerator, hung the tail out all over the road, rev counter thrashing into the red, blast of horn from the truck, ferocious hoot from a taxi as I rocketed clean across his bows – Christ, a bicycle – missed the back wheel by an inch. MGB going slowly down the outside lane, but I won’t get in front. Hurry, MGB, for chrissake – oh shit, XJ6 belting down second lane – move your ass MGB. The gap opened and I got out of the path of the XJ6, and behind the ass of the MGB, down the tiny slip road in the central divider which was the last exit before Hyde Park Corner, and away from the jam that the Marina now had no chance of missing.

As I started to drive back up Park Lane, I could see the Marina, still in the inside lane on the far side of the carriageway. Both driver and passenger were looking my way, and while I was too far away to see and memorize their features, I could, even from this distance, make out the expression on their faces: they looked very pissed off.

I pulled a receiver from my pocket and put it in my ear. Then I took my propelling pencil out, and spoke into the clip. ‘This is Ursula’ – Ursula was my code name for the day – ‘I want urgent tail on navy Marina registration AEX 659Y. Currently in southbound jam at Park Lane-Hyde Park junction. And gen too.’

‘Roger Ursula. Reply Halo.’

The words ‘Reply Halo’ told me on which of the channels the reply would be coming. When we were in contact with Central London Control, or with any other central control point – there were several in key cities across Britain – to minimize the risk of one’s conversation being monitored, each radio transmission would be made on a different frequency. If I wanted to speak to CLC again, it would next be on the frequency for which Halo was the code. I set the dial on the pencil to this frequency and switched the transmitter off to conserve the battery; it would be some minutes before the reply came.