‘Nothing really. I’m a bit hard of hearing, you see.’ Müller could hear a television or radio blaring away at full volume from inside the flat. ‘I have to put the TV volume on its highest setting, and when I do that I can’t hear much else. It’s a wonder I heard you ring the bell just now.’

Müller realised further questioning of the man would be next to useless, especially as he’d already been ‘got at’ by Bahlow’s men.

It wasn’t until about the twentieth apartment she tried, one on the first floor, that Müller finally made some progress.

Her first thought when the young woman – replete with safety-pin piercing her right nostril and bright-orange spiky hair – opened the door was that she was unlikely to get much co-operation. Punks were notoriously anti-police, thanks to the amount of surveillance and hassle they encountered. But this young woman defied the mould, and was friendliness personified.

‘I was just making a coffee. Would you like one? There’s enough in the pot,’ she asked.

‘That depends. I’d love one, but I’m working. So is there anything you can tell me about the night in question?’

‘There is indeed, officer. Quite a lot. So, the coffee?’

‘That’s kind of you. Milk, no sugar.’

While the young woman busied herself in the kitchen, Müller had a nose around the living room. ‘Do you live here alone?’ she shouted. The photograph on the bookshelf seemed to imply she didn’t. The woman’s arms wrapped round another – older – punk, a man who was slightly less flamboyantly dressed. As Müller turned away from the photo, the young woman was back with coffees. The pot must have already been on the stove.

‘That’s my husband,’ the woman said. ‘He’s a lecturer at the university.’ Müller raised her eyebrows – and the woman clearly registered the look. ‘Yes, don’t worry. He gets plenty of grief for his appearance, although he tones it down during the daytime. I was his student – I still am a student. That’s why I’m here at the moment. Supposed to be revising for exams.’ Her eyes flicked to the dining table, full of half-open textbooks and sheaves of notes. Then she gestured to the sofa – an orange corduroy affair: an almost exact match for her hair. ‘Shall we sit here and then I can tell you everything?’

‘Let’s start with your full name, please,’ said Müller.