‘So how about a punctured windpipe, Elsa? My guess is that the victim was awake all the time. Even with an open wound in his windpipe. He was always awake. That’s what I think. What do you think, Elsa?’

‘I know exactly what you’re asking, Max, and I’m not going to give you an answer. Because I just don’t know! And there’s no way I could possibly know for certain.’

A waiter brought a bowl of kim chi and placed it in front of Elsa. She did not look at the waiter, the kim chi or me. She stared out at Glasshouse Street, which is really little more than a glorified alley that runs parallel to Regent Street, and she sighed, shaking her head.

I did what I had seen Mallory do. I let the silence between us grow and waited for her to fill it. And eventually she did.

‘A body only has to lose approximately a fifth of its normal blood volume to produce hypovolemic shock. Lose that amount of blood and the heart stops pumping. Veins dilate, blood pressure drops, and eventually—’

‘You flake out.’

‘Yes. If we’re going to use the medical term, you flake out.’

‘But that didn’t happen to Piggy because he didn’t lose enough blood. He lost a lot of blood – a hell of a lot of blood – but not enough to put him out.’

‘That’s a reasonable supposition.’

‘So the killer sticks the blade in his neck, cuts through the windpipe, but doesn’t finish the job – something spooks him – and he lets the man slide from his arms. But Philips doesn’t black out. Just so we’re clear, he doesn’t black out, right?’

Elsa reluctantly nodded.

And then finally she gave me what I had come to Soho to find.

‘I know what you are asking, and the answer is yes,’ she said. She picked up her chopsticks and selected a slice of kim chi. The chilli soaking the napa cabbage was as bright as fresh blood. ‘There’s a good chance Guy Philips saw his assailant’s face.’

A uniformed sergeant was outside the main entrance to the hospital, red-faced and stamping his boots.

‘He’s still alive,’ I said.

It wasn’t a question.

The PS gave me a grin, indicating the deserted street outside the private hospital. ‘You’ll know soon enough when he’s snuffed it,’ he said. ‘They’ll all come running.’

I nodded. The death of Guy Philips would swamp the street with cameras and microphones because then we would have a serial killer.

There was another uniformed officer outside the lifts. I didn’t recognise him and I had my warrant card in my hand before I reached him.

‘All quiet?’ I said.

‘These nurses keep bothering me, sir,’ he said. ‘They love a man in uniform.’