He clearly runs his house like he ran his courtroom. I find a leather armchair and once I’m in it he wheels closer, bringing his canister with him. At one point it nearly tips over and Kush lunges for it. Luckily I have the leash held tight so I just about manage to stop a major incident. I go to help right the canister but Muller waves me off and I’m forced to watch his slow and laborious progress.

What a change grief can make. Before, he was a powerful man, the type who have a density about them capable of pulling together whole rooms of people. Now he’s shrivelled down, whatever illness landing him in his wheelchair undoubtedly induced by the stress of his daughter’s murder. I’ve seen it happen before, the death of a loved one like the first domino to fall.

‘So why are you here?’ he says once he’s finally finished.

I sit forward in the chair and tell him about Marianne Kleine’s murder, how the particulars match exactly that of his daughter’s death. He listens with an intense stare which makes me think his eyesight’s deteriorated.

‘I know you, don’t I?’ he says when I’ve finished.

For a moment I wonder about brazening it out, but decide it’s probably not worth it.

‘I was the investigating officer in the case of your daughter’s murder, yes.’

There’s a long pause whilst he nods his head ever so slightly, eyes fixed on me.

‘Yes, I remember now. I didn’t think you were doing a very good job at the time. You and that other one.’

‘Hank de Vries –’

‘Yes, that’s the one –’

‘– is in a coma, injured in the line of duty.’

‘Well, sorry to hear that,’ Muller finally says with a distinct lack of real feeling, at least to my ears. ‘But I still don’t understand why you’re here.’

Before coming I’d done a little digging on DH Biotech. The main thing I’d discovered was that the man in front of me and Marianne Kleine’s father had both been there during a two-year period before Muller left. What my digging didn’t tell me is what contact they may have had during that time. So I start by asking him about the company.

‘What about it?’

Am I imagining it, or has he just sharpened up? I tell him about Kleine’s father, Pieter-Jan.

‘Never heard of him,’ he says. ‘I was on the board. The only people I dealt with were the COO and the CFO.’

‘He was head of research; he never presented anything to the board?’

‘Maybe, I can’t remember. It was years ago after all, and a lot has happened since.’

‘Tell me about the company.’

‘Why? It has nothing to do with anything.’

‘Just indulge me.’