Ulrich stared at him for a while. He didn’t like what he saw and he certainly didn’t like what he was hearing. The man was naïve and complacent at best. He didn’t trust him when he said he’d revealed little detail about the market. On the other hand, as far as he could tell, the man hadn’t been followed to Moselstrasse, and most importantly, Ulrich now had the money.

Wolfgang would be delighted. He could get the escape line working again and move Friedrich on.

He looked up: the Englishman was wringing his hands and had a sheepish grin on his face as if aware he’d done something wrong.

‘May I go now?’

‘I think you better had.’

After he had left, a man appeared from the shadows where he’d been hiding. He brushed the dust from his coat and hair and glanced at Ulrich, who looked relaxed in the armchair.

‘You heard all that?’

The man from the shadows nodded.

‘So you know what to do?’

He nodded again and left the cellar.

Sorensen’s team followed the one-armed man in the leather jacket and woollen hat as he walked up Moselstrasse, crossing Kaiserstrasse before turning right into Taunus Strasse. Walt, the senior member of the team following him, said the man was a professional, increasing his pace without it being obvious and using classic techniques to be sure he wasn’t being followed.

‘I’m going to cut radio contact for a while. I’m worried he’s heading for some kind of transport. I’ll see what we can do.’

It was an hour before they heard from Walt again, during which time even the unflappable Sorensen began to appear agitated.

‘He headed to Landstrasse, where there was a motorbike waiting for him: fortunately we’d pulled both our cars up by then and were able to follow him. He headed north-west out of Frankfurt and up into the Taunus mountains.’

‘Where are you now, Walt?’

‘A spa resort called Königstein; it seems really nice and peaceful.’

Sorensen arranged for a car to take the three of them to the town. The building Ulrich had been dropped at was a former guest house set in a quiet road with the mountains looming behind it. They met Walt diagonally opposite the house in an abandoned building he’d taken over.

‘The roof’s damaged, but as far as we can tell, the building is inhabited. We’ve been watching it for an hour now, maybe a bit longer. The ground floor seems to be very secure, and there is some movement on the first floor. The windows are shuttered, but we’re working on the assumption that they can see what’s going on outside. I’ve got three men watching the rear and the sides, and two at the front.’

‘I don’t suppose you have any idea of how many people are inside?’

‘My guess is at least two. We watched the one-armed man go in, and there was definitely someone moving around the first floor when he arrived.’

‘Is there any reason why you can’t call for backup and move in?’ Prince was watching the house through binoculars.