‘You misunderstand,’ said Lady Ty. ‘I don’t care what her involvement is – I want her kept out of the case.’

She really had no idea what she was asking for, but I knew better than to try and explain.

‘Understood,’ I said.

‘And Peter,’ said Lady Ty, ‘Nightingale is not to know about this – is that clear?’

‘Crystal,’ I said.

As soon as she hung up, I called the Folly.

‘I rather think I’d have to have taken an interest in any case,’ said Nightingale once I’d briefed him. ‘Still, I shall endeavour to adopt a façade of ignorance until such time as you need me.’ He paused and then said: ‘And you will let me know when that moment arrives.’ It was not a question.

‘Yes, sir,’ I said, and hung up wondering why everyone felt the need to be so emphatic at this time of the morning.

Beverley owns both halves of a 1920’s semi-detached house on Beverley Avenue in SW20. It’s a strange place, half-furnished and underused. Beverley told me when I first visited that she ‘sort of inherited it’ and hasn’t really decided what to do with the property yet. She sleeps in a ground floor room with easy access to the back garden. There’s just the Ikea bed with an incomprehensible name, two mismatched wardrobes, an antique mahogany chest of drawers and a Persian carpet that covers half the bare floorboards.

I reached out and felt the empty side of the bed – there was just a trace of warmth and a hint of oil on the pillow – Beverley had slipped away hours ago. I sighed, got out from under the warm duvet and shivered. The French windows were half open, letting in a cool breeze and the smell of rain. The bathroom upstairs didn’t have a shower so I had a quick bucket bath in the huge oval tub, which I knew from happy experience easily accommodated two people at once, and got dressed.

Everything related to operational matters in the Met is monitored. Which means you can’t just open your AWARE terminal and go fishing for information without having a damn good excuse.

So while I was buffing up my shoes I called DC Guleed, who I knew was doing the night shift in the Homicide Assessment car that week.

‘Hi Peter,’ she said. Behind her I could hear a hushed indoor ambience and people being professional.

I asked whether she’d heard of a shout in Knightsbridge, a suspicious drug-related death.

‘Why do you want to know?’ asked Guleed, which I suspected meant she was on the scene.

In the background I heard a vast and familiar Mancunian voice demanding to know who Guleed was talking to – DCI Alexander Seawoll. Who, as SIO, shouldn’t even be out of bed until the Homicide Assessment Team had finished their work.

‘It’s Peter,’ she called back. ‘He wants to know about our suspicious death.’