‘Beving wants to see you.’

Upstairs Beving tells me to close the door behind me.

‘I get the feeling you’ve been avoiding me,’ he says.

‘Been busy. On the case.’

‘You’ve not forgotten our agreement then? I was thinking maybe you had.’

‘Not forgotten, just nothing to report.’

He eyes me suspiciously, before reminding me that it’s only because of his good grace that I’m here at all. Once I get out of there I head back to what I was doing before being interrupted.

DH Biotech was formed in 1981 by the Swiss biochemist Didier Hoffman. Hoffman, like his far more famous namesake and discoverer of LSD, Albert, had initially worked for Sandoz. But, for personal reasons, he’d eventually left to strike out on his own. There’d been a lawsuit at the time, his old employer saying he’d taken research that they owned with him, but a court of law found in favour of Hoffman. After that the firm grew rapidly, partly because Hoffman had set up a division to oversee clinical trials for other pharmaceutical companies and help them navigate the FDA approval process – necessary for access to the very lucrative US market – which allowed him to continue his research, the reason he’d become a biochemist in the first place. When he was twelve his father had been diagnosed with multiple sclerosis. Watching the pain and deterioration over the next fifteen years was probably what drove Hoffman towards investigating novel ways to at least slow the disease’s progress, if not halt it entirely. His area of research was based on a particular part of the immune system, the over-activation of which held, he believed, the key. None of which is really making anything clearer for me. I’m starting to think Muller was right, it is a coincidence. Just one that’s hard to swallow. I turn to Marianne’s father, Pieter-Jan Kleine, and start reading up on his background when a voice startles me from behind.

‘I’ve got the culprit, sir.’

I turn to see Jansen standing at the door, pointing to Kush who I see has wandered over to Jansen’s desk just on the off-chance. I call Kush over, and he reluctantly stops sniffing around the closed drawer and comes across with a very teenager-like slouch. He glances at Jansen as he passes him but doesn’t stop.

‘Look, about the shoes, I’ll –’

‘It’s all right, sir. I got over it. But I wanted to say I just had a phone call. Someone did pick up some mail from the charity’s PO box.’

‘Did they follow them?’

‘Got an address right here.’ He hands me a slip of paper. It’s some kind of clinic on a street in Amsterdam-West, an affluent neighbourhood.

Vermeer walks in. I bring her up to speed.

‘Think we should check it out.’

‘I agree,’ she says.