There was a call-box in the darker part of the lobby. I opened the door and stepped inside. It smelt as if someone had kept a goat in there at one time, and not a particularly nice goat at that.

Holding my breath, I hung my handkerchief over the ancient mouthpiece, lifted off the receiver and dialled.

After a while a voice bellowed: ‘Police Headquarters. Sergeant Harker talking.’

‘Connect me with Lieutenant Mifflin,’ I said, speaking away from the mouthpiece. I probably sounded at the other end like Hamlet’s father’s ghost.

‘Who’s that?’

‘Harry Truman,’ I said. ‘Make it snappy. You may not think it but time’s money to me.’

‘Hold on,’ the sergeant said. I heard him call across the room, ‘Is the Lieutenant in? There’s a guy wanting him. Says his name is Harry Truman. That’s familiar, ain’t it? I’ve heard it before somewhere.’

Someone called the sergeant a very rude name.

Then Mifflin came on the line.

‘Lieutenant of the Police talking,’ he said sternly. ‘Who’s that?’