It was all far too easy for Müller’s liking. The whole thing stank of a Stasi stitch-up. But without proof, they would simply have to go along with it. She looked at the name and address on the sheet. Bodo Achterberg, aged fifty-eight, a refuse collector. Address: Hetzdorfer Straße 11, Gorbitz.

She eyeballed Bahlow. ‘Have you questioned the neighbours who reported him missing yet?’

‘No,’ replied Bahlow. ‘We didn’t want to tread on your toes.’ Müller turned to Tilsner and saw him rolling his eyes.

The two detectives began to get to their feet. As they did, one of the new pieces of technology in Bahlow’s office beeped into life and started printing something out. He got up and tore off the sheet. ‘Aha! That’s interesting. Normannenstraße are speculating where our friend Gustav got his name from, assuming – as they suspect – that he’s an imposter.’ He handed the sheet to Müller. It was a fax – containing a representation of a painting of the Alps. ‘Gustav Weiß was a Swiss painter – I suspect that may be where the name has been borrowed from.’

Müller handed the picture back. She couldn’t help feeling she and Tilsner were simply pawns in a game – a game that was being controlled by the Stasi. ‘So why was he at Lotti Rolf’s?’ she asked.

Now it was Jäger’s turn to intervene, as he rose to see them out. ‘We’ve no idea, Karin. Perhaps he was simply a burglar and that’s his modus operandi – posing as a Stasi officer. Very few people would be prepared to challenge that.’ As he guided the two detectives to the door, he took Müller to one side. ‘There’s something else I wanted to talk to you about, Karin. But perhaps we should go for a drink one evening.’

Going for a drink with Jäger was about the last thing she wanted to do. Better to let him say what he wanted here and have done with it. ‘What is it now?’ she asked.

‘Nothing to be concerned about.’ He lowered his voice, speaking softly into her ear. ‘It’s just we have a mutual interest in the Rosa-Luxemburg-Sportschule in Oberhof.’

‘Oh yes.’ The thought of the children immediately made her feel guilty. She would have to make time to visit her mother – and Johannes and Jannika – at the weekend.

‘Yes. I don’t think I’ve told you yet. My son was selected to go there last autumn. He’s very good with a rifle – all those hunting trips with his father. And he’s not a bad cross-country skier either – so they think they may be able to make something of him as a biathlete. And I gather your twins go there too now?’