‘In Pirna, Bad Schandau, or Dresden?’

‘The latter.’

‘Have you arrested her?’

‘That’s not in our interests. However, I can tell you where you can find her.’ He produced a Dresden street atlas from his pocket – Müller recognised the green cover. She and Tilsner had exactly the same one in the Wartburg. He turned to the maps section at the rear, and plate thirty-one. ‘Very occasionally, she stays at the Rolf’s run-down cottage in Kirnitzschtal – you know that. You very nearly caught her there.’

So the warm coffee cup had been Lotti’s, as Müller and Tilsner suspected. And the two men watching from a distance had obviously been Bahlow’s men.

‘But most of her activity is in the confines of the city. Here, on the eastern edges of Dresden, there are a couple of passenger ferries. The first connects the northern end of Niederpoyritz to an area of common land next to the Elbe, by Tolkewitz. The second is about a kilometre upstream, connecting the south-eastern part of Niederpoyritz with Laubegast. She’s been spotted using both of those ferries. She’s also been seen on the Standseilbahn about three kilometres to the north-west of the first ferry.’

‘The Schwebebahn?’ asked Müller.

‘No – not the suspension railway. The cable railway. It starts at virtually the same point in Loschwitz, goes up a similar hill to the Weißer Hirsch, but it travels along the ground.’

‘All right,’ said Müller. ‘But what I don’t understand is why you’re giving me this information.’

‘She knows we’re on to her. Each time we’ve spotted her, she’s managed to lose our agents.’

‘But surely you can’t expect the Kriminalpolizei to do a better job of tailing someone than the Ministry for State Security’s own agents?’

‘There are complications,’ said Bahlow.

‘Like what?’

‘Like the man posing as a Ministry agent at the Rolf’s annexe in Kirnitzschtal. He is an agent, but he doesn’t work for us.’

‘You know who he is, then?’

Bahlow nodded. ‘His name is Gordon Breitmann – at least, that’s the name he uses some of the time.’

‘Gordon doesn’t sound like a very German name.’

‘He’s not German, although his family were originally of German extraction. He’s British. MI6.’

Müller stared hard at Bahlow. What game was he trying to play – and trying to get Müller and Tilsner involved in? If what he said was true, then this ought to be the Stasi’s area of operation, not that of the criminal police.

She gave a long sigh. ‘I still don’t understand why you’re giving us this information, rather than acting on it yourself.’