‘You checked they didn’t have any friends in common?’ I ask Jansen.

‘Nothing.’

I glance at the map on the far wall, the location of Kleine’s death marked by a red dot.

‘We need a map of the entire country.’

‘What are you thinking?’ Vermeer asks.

‘Apart from both being killed in the same way there’s so far been no link discovered between Muller and Kleine. And the person convicted of killing Muller is not only in prison, he’s incapacitated. And yet someone killed Kleine in exactly the same way. So far the only possibles have been Jan Akkerman and Robert Huisman. Huisman has conveniently disappeared and we’re still trying to locate Akkerman. But assuming that either he or Huisman, or both of them, are responsible for a moment, we’ve still got the question why? Why these two victims? They’re both young women, but neither showed any sign of sexual assault, and they both look different – different hair colour, different style, different body shapes – so they’re not an obvious type. So why did he pick them?’

‘Could just have been opportunity, sir?’ says one of the bright young things, a woman with dark shiny hair tied tight in a bun and quick, focused eyes.

‘Could be, but the way of killing seems so specific, so planned, that I can’t help think there’s more to it than that.’

‘Do you think they knew their killer, sir?’ Jansen asks.

‘I’ve got no evidence to say they did know their killer. It’s just a theory, which is our job to prove or disprove. And part of that is ruling in or out any connection between the victims. Let’s get a map of the whole country up and track their movements on it.’

‘How far back?’ Jansen asks.

‘Couple of years before Lucie’s death at least. Maybe more.’

Jansen nods, though I can tell he’s sighing inwardly; what I’ve just tasked him with is massive.

‘And we also need to keep in mind that this may not stop with Marianne Kleine.’ I look around the room, making sure everyone’s tuned in. ‘Two identical deaths, what’s to say there won’t be a third?’

‘What, in another seven years?’

‘Seven years, seven months, who knows? But it’s our responsibility to make sure it never happens.’

The team gets to work, Vermeer disappears, and I decide to drop in on Roemers, to see where he’s got on the payment Huisman made just before Kleine’s death. I head to the tech department, an airless room in the basement where Roemers is king, only to find the chair at his desk is empty. When I ask the nearest person, a middle-aged man who blinks a lot and never quite looks you in the eye, where Roemers might be all I get is a shrug and something about Roemers keeping his own counsel.