‘Feel free,’ said Tilsner. ‘This is our case. Your lot just have a watching brief. Go and ask Bahlow in Dresden if you don’t believe me. So why don’t you just get out of here, now, before I actually squeeze your windpipe properly?’

The man started to move off, taking a folder with him.

‘What’s that you’ve got?’ asked Müller.

‘It’s none of your business,’ replied Weiß. Tilsner snatched the folder from his hands and began leafing through it.

‘Oi,’ shouted the man. ‘That is Ministry for State Security property.’

‘What is it, Werner?’ asked Müller.

‘More letters between Lotti and Arnold Southwick. Letters that are evidence in our murder inquiry.’

The man made a grab to try to snatch the folder back in turn, but Tilsner was too quick for him. With one hand, he shoved the man away by pushing into his face, with the other, he shielded the folder behind his body.

‘As I said,’ reiterated Tilsner. ‘This is evidence for our murder inquiry. If you want copies, you’ll have to talk to Bahlow.’

The man stared them both down for a moment, then turned on his heels. Müller followed him to the door, then watched him make his way back to the tram stop. To the side, leaning nonchalantly against a fence while enjoying a quiet smoke, were the two from the Lada. The two that Müller had assumed were also Stasi agents. Now, they were lazily watching Weiß but making no attempt to rendezvous with him. So if Weiß really was the Stasi agent, who the hell were the others?

*

Once they were back in Dresden, Müller’s first move was to seek an urgent appointment for her and Tilsner with Bahlow at Bautzner Straße, the Stasi regional headquarters on the opposite – northern – bank of the Elbe, in Dresden Neustadt. Claiming she had important new evidence, she managed to secure a meeting within the hour.

The Stasi’s administrative offices here were much like many others in the Republic. A fairly featureless, grey concrete affair, prettied up with screen walls of decorative concrete blocks. Müller had a fairly good idea what it would look like round the back of the building, however. Probably a mirror image of the Stasi prison in Bautzen itself – the town some sixty kilometres to the east which lent the street they were now on its name – complete with walls, barbed wire, and an internal brightly lit garage where new inmates would be processed.

Müller and Tilsner were led down a couple of corridors and then up a staircase before finally being shown into Bahlow’s office.

As soon as they were through the door, Müller’s heart sank.