When Ethel had caught us up, Mavis stopped for fuel, and Sheila sat behind Whalley. Just after half past eight, the left indicator of the Cavalier started flashing, and the car pulled off the road onto the crowded forecourt of a pub. Sheila’s driver, evidently numbed with the monotony of the tail, nearly rammed him up the back, his car snaking about the road with a howl of rubber; he then hooted angrily, flashed his lights and accelerated sharply forwards, which was textbook procedure for a near-accident when tailing. Whalley would never see that car again.

I pulled up a hundred yards past the pub and spoke into the microphone. ‘She’s gone in the German cruiser.’ German cruiser was rhyming slang for boozer. Cockney was alive and well and living in British Intelligence.

Ethel went past me, and didn’t stop, but I knew a short way up the road he would turn round, come back and find a discreet place to wait and watch the pub’s entrance. Mavis would be waiting a hundred yards or so back from the pub, also with a clear view of any vehicle or person leaving it.

I got out of the car and sprinted back towards the pub. As I came in sight, I stopped running and began to walk normally. A dark-coloured Capri – bottle green, I thought, but couldn’t be sure in the poor lighting – pulled out of the parking lot, with one man at the wheel and no one else in the car.

‘Pick up a fare, Mavis.’ I spoke into my breast pocket, whilst memorizing the Capri’s number at the same time. I had instructed the Chrysler to follow the Capri. There was probably no connection between the Capri and Whalley’s stop, but having come all this way, I wasn’t in any mood to take chances.

I could see Whalley’s Cavalier, empty. Whalley must have gone into the pub. I looked through the window into the lounge bar; it was a large L-shaped room, with chintzy, rose-coloured lighting, a long bar with a drab buffet selection at one end, and a battery of slot machines, including an ageing Space Invaders.