‘Of course not,’ Kneought Brodal retorts brusquely. ‘And neither was Stuub. The only thing I can confirm is that this was the potential link he was investigating, and it looks as though he found some data to support his hypothesis. But you have no idea how many scientists claim to have found all kinds of correlations that turn out not to hold up to rigorous scrutiny. Not least in order to drum up new research funds.’

I may have some idea, Karen muses, picturing the alarmist headlines in the evening papers.

‘On the other hand, Stuub apparently had enough sense to not publish this half-baked,’ Brodal continues. ‘If he’d been sure, he would have made his findings known.’

Or used them to blackmail the Groth family, Karen adds inwardly. She thanks Kneought Brodal and ends the call. Ten seconds later, she is dialling Dineke Vegen’s number. The prosecutor listens to Karen’s summary without interrupting.

‘All right, you can arrest Björn Groth. But a motive isn’t enough. We’re going to need more to charge him.’

‘A strong motive,’ Karen points out. ‘And we have the email from Stuub to Björn Groth as well.’

‘Sure, but you need more if you want it to hold up in court. How on earth is it possible that no one saw or heard anything? Are people blind as well as deaf up there in hinterlands?’

Not entirely, Karen thinks to herself, but she says nothing. We actually have a statement from someone who is refusing to testify about something that was said by someone who is no longer able to verify it. Completely unusable unless I can get Odd to change his mind. Or I break my promise.

‘You have three days,’ Dineke Vegen says. ‘Make them count.’

Her conversation with Cornelis Loots is almost as brief. She quickly explains that the prosecutor has given them the green light; Björn Groth is to be arrested and they have warrants to search both his business and his home. They have three days before they have to charge him or let him go.

‘Go up there right now and take Byle with you; I’ll meet you there to make the actual arrest. I’m going to call Larsen and ask him to send up technicians to do a first sweep before we go in.’

‘OK, but what about Groth’s wife?’

‘We’re going to cordon off the whole place, so she has to find somewhere else to sleep tonight. And make sure you bring a couple of uniforms to drive Björn Groth to the station.’

‘We’re going to keep him in Lysvik for three days?’ Cornelis says in disbelief. ‘I don’t think the station’s holding cell is up to standard, is it?’

‘No, it’s only approved to hold people for twenty-four hours. We’re going to have to take him down to Ravenby. You and I will do that tomorrow.’