I checked the time. It was three thirty in the morning, less than four hours after Nightingale had been shot. If you work for any time in a large institution you start to get an instinctive feel for its bureaucratic ebb and flow. I could feel the hammer coming down, and since I’d only been a copper for two years, the fact that I could feel it coming meant that it was a very big hammer indeed. I had a shrewd idea about who’d put the hammer in motion, but there was nothing I could do but stay sitting on the wrong side of the interview table with my cup of bad coffee and two chocolate biscuits.

Sometimes you have to stand still and take the first blow. That way you can see what the other man has in his hand, expose his intentions and, if that sort of thing is important to you, put yourself unequivocally on the right side of the law. And if the blow is so heavy that it puts you down? That’s just a risk you have to take.

The blunt instrument chosen caught me by surprise, although I made sure I kept my face neutral when Seawoll and Detective Sergeant Stephanopoulos entered the interview room and sat down opposite me. Stephanopoulos slapped a folder down on the table. It was far too thick to have been generated in the last couple of hours, so most of it must have been padding. She gave me a thin smile as she ripped the cellophane off the audio cassettes and slotted them into the dual tape machine. One of those tapes was for me, or my legal representative, to prevent me being quoted out of context; the other was for the police to prove that I had copped to the charge without them having to beat me around the back, thighs and buttocks with a sock full of ball bearings. Both of the tapes were redundant because where I sat was neatly framed in the viewfinder of a CCTV camera mounted just above the door. The live feed went to the observation room down the corridor where, judging from the theatrical way Seawoll and Stephanopoulos had made their entrance, someone of ACPO rank was watching – the Deputy Assistant Commissioner at the very least.

The tape machine was turned on, Seawoll identified me, himself and Stephanopouois as being present and reminded me that I was not under arrest but merely helping police with their inquiries. Theoretically I could stand up and walk out any time I liked, provided I didn’t mind kissing my career in the police goodbye. Don’t think I wasn’t tempted.

Seawoll asked me, for the record, to outline the nature of the operation that Nightingale and I had been running when he was shot.

‘You really want that on the record?’ I asked.