I wanted to spend the night at Bev’s but I needed to be central in case Martin Chorley did something viciously psychopathic in the middle of the night. As it happened, I got to sleep all the way to nine thirty the next morning before the landline rang and Stephanopoulos told me that somebody had just tried to kill Olivia McAllister-Thames.

The house opposite Tyburn’s place had obviously been built post-war, probably to replace bomb-damaged stock. Mercifully it must have been quite late on because it wasn’t the featureless box so favoured by the American modernists, and the architect had actually made an attempt to fit it in with the rest of street. It still had a touch of the gun emplacement around the ground floor and a marble floored entrance hallway that managed to be both pretentious and dark at the same time.

Once I was safely cocooned in my noddy suit, Stephanopoulos led me upstairs to the third floor flat where the sniper had made his nest. I’d missed the body, which didn’t bother me, but Stephanopoulos had a tablet stuffed full of crime scene photographs.

‘We don’t know who he is yet,’ she said. ‘White, mid-thirties, fit, has a Foreign Legion tattoo but that doesn’t mean anything.’ As police we were always tripping over people with special forces tattoos that were more aspirational than indications of service.

‘I’m hoping for distinctive teeth,’ said Stephanopoulos, although that was no longer the reliable guide to nationality it once was. I’d been told that American dental work was still distinctively overwrought – whatever that meant with regards to teeth.

‘Let’s hope he wasn’t American,’ I said. We didn’t need any more about that complication thank you very much.

The flat was unfurnished, although in a distinctively expensive way with marble flooring in the bathrooms, Italian tile in the kitchen and expensive rosewood parquet in the rest. The nest was in what I’d call a living room but was probably listed by the estate agent as the lounge. The firing position was a good three metres back from the bay windows. The central window had been opened and securely fastened, but with the curtains partly drawn he’d have been in shadow – essentially invisible from across the street.

The lack of furniture meant that he’d had to bring his own stand to rest the rifle on, the heavy duty type serious anglers use for big fish. He’d even brought a campstool, a couple of bottles of water and a packet of Pret a Manger sandwiches. I imagined a couple of DCs were even now pulling the CCTV footage from every Pret within a kilometre.

Damn – that was going to be a lot of Prets.

I glanced around the empty room.

‘He knew there wasn’t any furniture,’ I said.