‘Shh,’ soothed Müller. ‘If you don’t want to draw attention to this little meeting, you need to try to calm yourself, Olga.’ Müller used the woman’s first name to try to get through to her, even though she hadn’t been invited to. It seemed to do some good. The woman tried to choke back her tears, and Müller could feel her physically bracing herself. ‘Take some deep breaths,’ said Müller. ‘That will help.’

Voights proffered the briefcase once more, this time to Müller alone. ‘Heinz said that if anything ever happened to him, I had to pass this on to someone I trusted. Someone who would help the truth get out. And I needed to be sure that person didn’t work for the Stasi. Can I trust you?’

‘I hope so, Frau Voights. But before I take the briefcase, do you have any idea what the documents contain?’

The woman nodded, and lowered her voice still further. ‘There’s something strange going on here.’

‘Where?’ asked Müller, looking around her at the dense forest. Wondering if – despite everything – Voights might be nothing more than mentally deranged.

‘Not here in the forest. At the school.’

Müller started to become alarmed. ‘My twin children go to the school.’

‘How old are they?’ asked the woman, sounding concerned.

‘Not even six years old yet,’ replied Müller.

The woman appeared to sigh in relief. ‘That’s all right then. The really young ones aren’t involved. You’ve no need to worry at the moment. But my advice would be once they reach puberty, their early teens, you need to get them away from here. Perhaps sooner.’ Now it was the woman clasping Müller’s hands rather than vice versa. ‘Promise me you’ll do that.’

Müller nodded, then started to open the briefcase. Voights slammed it shut again. ‘Not here. It’s not safe. Did you come from Dresden, where . . . Heinz . . . where Heinzi . . . died.’

Another nod from Müller.

‘Take it back there, then. You’ll need to get a scientist to go through it with you, anyway. Someone who understands chemistry, and biology, and can decipher coded information. Otherwise it will just be sheets and sheets of meaningless data. But I need you both to promise me you will try to bring this out into the open, and put a stop to it.’

‘Of course,’ said Müller, giving the woman a hug. ‘I promise I will.’

‘And you,’ said the woman, directing a fierce gaze towards Tilsner, who’d been unusually silent for the past few moments.

‘Absolutely,’ he said. ‘I am Hauptmann Müller’s deputy. Her word is our bond.’

*

In the end, taking the children to Rosamund’s proved trouble free. And both Jannika and Johannes were thrilled to see her.

‘Is he your new boyfriend, Mutti?’ asked Jannika, staring hard at Tilsner.