I wanted a cigarette the way I always did when faced with a problem. I fought the feeling down and considered my options. Even a contortionist couldn’t have got a shot taking in the number plate of the Mercedes and the front of the flats.

And what was that worth anyway? I anticipated Alistair Menzies’ contemptuous smirk. I could scout the block, maybe get a line on who lived there. I wasn’t looking for Brigadier and Mrs Top-Drawer after all. But it felt scrappy, not semi-professional. There were at least six flats in the block. I tried to tell myself that I’d achieved something-found an assignation point, a field for further investigation. I wasn’t convinced.

Minutes ticked on, but fewer of them, I found later, than I thought. Truth to tell, I was nervous and that distorts the sense of time. I was anxious not to screw up my first job.

‘Patience, Cliff,’ I muttered. ‘Turn your weaknesses into strengths.’

That’s when I became aware of the movement in front of me. It wasn’t much, just the half-caught motion of a branch, a lightening or deepening of shade. I’d fought the Chinese guerrillas in Malaya and learned to take notice of things like that because my life depended on it. There was someone else watching the flats, someone positioned closer than me. I squinted in the failing light, trying to isolate the spot. Not near the tree opposite mine on the other side of the street, not in the narrow garden fronting the flats, but somewhere. Two tall trees flanked the entrance to the driveway marked Residents Only. Poplars with bushy trunks. Maybe there.

I wasn’t really alarmed. When I’d worked as an insurance investigator it wasn’t so unusual to find more than one guy operating on different sides of the same street. You suspect a workers compensation claimant of faking and set out to prove it. He suspects his insurance company’s bad faith and you have competition and confrontation. It happens all the time. I’d got the range and was pretty sure the movement was in the poplars, when Charles Meadowbank and his companion came out of the flats. She was a tall brunette wearing a blue silk dress that shimmered as the overhead lights caught it. High cheekbones, sculptured features, up-swept hair. I got the camera into position.