‘I really don’t see what that has to do with anything, Herr Hauptkommissar …’ Fabel felt as if he were looking in through a metre of lead glass into the heart of a nuclear reactor: witnessing something uniquely powerful and deadly, but contained.

‘It’s just that the Ukraine has featured so prominently in our investigation.’ It was true; but how would Eitel interpret it? Fabel paused, inviting him to comment.

Wolfgang Eitel smoothed the ivory hair at his temples with the heels of both hands. But it was his son who spoke: ‘We have business interests across Europe and beyond. We own publications in the Netherlands, in Poland, in Hungary. Our property business involves partners in the United States as well as those in the Ukraine. I don’t see that that is, in itself, particularly newsworthy.’

Bull’s-eye. Fabel and Maria exchanged a quick, surreptitious look. Fabel fought to keep the exhilaration of discovery from his expression. He again addressed Wolfgang Eitel.

‘I think we all know that Frau Blüm’s article was based on more than a simple deal with eastern-European business partners, don’t we?’

‘Then you know more than I, Herr Fabel.’

Waalkes, the lawyer, interrupted. ‘I think this has gone quite far enough, Herr Hauptkommissar. We have agreed to this interview because everyone here is horrified by Frau Blüm’s murder and we are committed to doing all we can to help catch this monster. But I have to say that your line of questioning seems both impertinent and irrelevant. You seem to be seeking to implicate my clients in some totally unrelated issue.’

‘I wasn’t aware we had accused anyone of anything,’ said Maria. ‘We’re simply trying to find the connection between the Eitel Group and Frau Blüm.’

‘And I think we’ve dealt with that.’ Norbert Eitel stood up to signal the discussion was at an end. None of the police officers followed his lead. Fabel addressed Waalkes.

‘I think it would be in everyone’s interest if both your clients supplied us with accounts of their movements on the dates of the murders we’re investigating, along with the names of anyone who can corroborate those accounts. And I’d be obliged if this could be done as soon as possible …’

‘This is outrageous!’ Eitel senior’s voice thundered as he rose to his feet with a swiftness that belied his age. ‘Are you accusing me or my son of involvement in these acts?’

Fabel, remaining in his chair, said, calmly: ‘It is a routine enough request, Herr Eitel.’ Maria handed Fabel a piece of paper on which she had written the times and dates of each murder. Fabel stood up and turned again to Eitel senior. ‘Anyway, Herr Eitel, I should have thought that you have had some experience of answering difficult questions …’

This time it was Waalkes who exploded. ‘That is quite enough, Herr Fabel! This is intolerable. I intend to notify your superiors about this …’

Fabel stood up and handed Waalkes the slip of paper. ‘Times, places, witnesses … I need a full account for both your clients.’ He turned to Norbert and Wolfgang Eitel. Eitel senior’s eyes were incandescent beneath the thick white brows. ‘Good day, gentlemen,’ said Fabel and led Maria and Werner from the room.