‘That is the strangest thing,’ said the man, perplexed but smiling. ‘That is quite definitely … absolutely definitely … a rhinoceros … But the guide states here that this panel dates back to the Middle Ages. I thought in Germany you would not know of such things at this time …’

‘Are you Spanish?’ Fabel spoke his mother’s language like a native and had an ear for foreign accents in English.

‘I live in Spain, but I’m Mexican, actually. Paco is my name,’ said the tourist and smiled broadly. ‘I am a writer and such things interest me.’ He shook his head in awe. ‘And this is a most interesting city …’

‘I’m afraid I have no idea. I’m from Hamburg myself …’

‘Maybe it was a family who traded with Africa,’ said Wagner. ‘But Cologne started off as a Roman city and had contacts throughout the Empire. It’s always been a trading centre for the rest of Europe. For the world. But I’m afraid I can’t tell you what the significance of the rhinoceros is.’

‘Thank you, anyway,’ said the tourist.

They were about to walk away when Wagner checked himself. ‘Oh, there is one meaning it might have.’

‘Oh?’

‘There was a lot of symbolism borrowed from pagan times to represent the various aspects of Christ. They were big on bestiaries in the Middle Ages and used exotic animals as symbols for Christ or the resurrection. The Phoenician myth of the phoenix and the image of the pelican were both used to represent the resurrection.’

‘Why the pelican?’ asked Fabel.

‘Back then they thought pelicans ripped open their own chests to deliver their young.’

‘And the rhinoceros?’ asked the tourist.

‘The rhinoceros was a symbol of Christ’s wrath. Righteous vengeance.’

‘Most interesting …’ said the Mexican. ‘Thank you.’

Fabel and Wagner left the tourist still looking up at the stained-glass window, shaking his head in wonder.

‘Impressive …’ said Fabel, with a smile.

‘I was brought up in a very Catholic family,’ said Wagner wryly. ‘A lot of it sticks.’

Fabel and Wagner sat on a pew near where the immense stained-glass window soared high and wide, splashing the floor’s flagstones with puddles of red, green, blue.

‘Amazing, isn’t it?’ said Wagner. ‘Did you know that Cologne Cathedral was the world’s tallest man-made structure until the end of the nineteenth century? It was the Eiffel Tower that replaced it, I think. Or the Washington Monument.’

Fabel nodded. ‘So much stone. No wonder it took three hundred years to build.’

‘This isn’t simply a place of worship: it’s a physical statement. A big statement. Big God and little us.’

‘I take it that despite your Catholic upbringing you’re not the most religious person, Ullrich?’

‘After going through the Vitrenko Dossier it’s pretty easy to believe in the Devil, if not in God.’

‘I’d like a look at the dossier. Would that be possible?’