‘Murder Bags were where modern detective work began,’ he explained. ‘They had two of them in the Yard from 1925. Always packed and ready to go. They contained rubber gloves, magnifying glasses, containers for holding blood, test tubes for fingerprinting, all sorts of gear. The Murder Bags came in when Sir Bernard Spilsbury saw a detective handling a dismembered body with his bare hands. They were the start of modern homicide investigation.’ He looked at me shyly. ‘What you do.’

He gently replaced the ruined old bag as if it was priceless. ‘The history,’ he said. ‘I love all the history.’

‘One thing I don’t understand,’ I said.

Greene looked at me.

‘Your colleague – the woman PC – told me that the dead banker was your first dead body.’

‘PC Wren,’ he said. ‘Edie. Yes.’

‘But that can’t be true,’ I said. ‘How long have you been in uniform, Greene?’

‘Six years.’

‘You must have seen more dead bodies than me,’ I said. ‘You must have averaged a dead person every day. Motorists who went through their windscreens while sending a text. Cyclists who got hit by a bus. Pedestrians who got hit by the cyclists and the motorists.’ I shook my head. ‘I can’t believe that Hugo Buck was your first dead body.’

Greene thought about it.

‘It’s true,’ he said. ‘I’ve seen a lot of dead people. But what Edie— what PC Wren and I found that morning, on the floor of that man’s office, it wasn’t rotten luck or fate or stupidity. It didn’t happen because somebody was drunk or stoned or sending a text message. What happened to that man, that banker, was the most deliberate thing in the world. It felt like a violation of everything. It’s not like the daily slaughter on the roads. I don’t know how to explain it. It’s just different, isn’t it?’

I nodded. ‘You’re right. Murder’s different.’

I wake too soon.

It is the sharp point of the night – too late to go back to sleep, too early to get up.

I slip out of bed and go to the window. The lights are blazing in the meat market. I come back and sit on the bed and I still haven’t looked at the alarm clock. It feels like catching the eye of a mad man.

And then I look.

03:50

I walk across to the big cupboard built into the wall and push the double doors. They spring open, and the collection of belts and necklaces hanging on the back of the door jangle softly in the dark.

There are shoes on the left-hand side. All kinds of women’s shoes. Strappy sandals and spike heels. On the right are stacks of drawers. Knitwear. Carefully folded jeans that will never be worn again.