‘So did you shine the torch at them?’

‘To be honest, it was either in Detlef’s or my pocket. I was carrying his box of gear – effects pedals, leads, that sort of thing – and he had his guitar and practice amp. We had our hands full.’

Müller’s heart sank. What had at first seemed a promising breakthrough was fast unravelling. ‘You must have been able to make out their height, build, hair colour . . . something?’ The last word was said with a certain hopelessness.

‘I’d say medium build. Perhaps the woman was a little thicker-set. Medium height too – nothing out of the ordinary. Middle-aged, or late middle-aged. Fifties or sixties I’d say. Not very old but certainly not my age, or your age come to that.’ The woman tugged at her hair nervously. ‘Sorry I’m not being much help here, am I?’

‘It’s not your fault,’ smiled Müller, trying to cover her frustration. ‘Anything else?’

‘I couldn’t see their faces or heads properly because it was bloody freezing, to be honest, both of them had dark-coloured anoraks or coats on, with the hoods pulled up and quite tight around their faces. I could see that the man was wearing spectacles, I remember that.’

‘Style?’

‘Quite big, round frames – possibly wire frames?’

‘Good, that’s useful.’ Petra smiled at the praise, pleased to have got something right. Müller couldn’t remember if that description tallied with the victim or not. The age did, certainly, but had he been wearing glasses? She’d have to check with Schriver’s team and the pathologist. ‘What I’d like you to do now, Petra, if that’s OK, is come out to the crime scene with me and show me exactly where the couple were standing. Is that OK?’

‘Of course,’ said the woman. ‘I’m happy to do anything that might help.’

*

Once outside the block, Müller looked for Schmidt. When she spotted him, rifling through a litter bin, she beckoned him over.

‘This citizen was the witness to an argument around the time our victim is thought to have met his death, Jonas.’ Schmidt was staring at the young woman dubiously through his pebble-thick glasses. His look betrayed his thoughts – why should the People’s Police give any credence to someone who dressed like that, with dyed hair, slashes in her black clothing, and a safety pin through her nose? ‘I want a photo of the position she saw the couple in, please.’

‘Of course, Comrade Hauptmann,’ said the forensic scientist. ‘I’ll just get my cameras from the car.’

While Schmidt was gathering his equipment from the rear of the Wartburg, Müller asked Petra Abt to try to position herself where the woman had been, and to guide Müller into the place where the man had been standing.

‘About like this,’ said Petra.

‘OK.’