‘Here I am,’ I said, squinting against the glare coming from the fountain. The square was fairly quiet, despite the fine weather. ‘And here you are.’

Patrik gestured for me to join him in sitting on the fountain’s edge. Once more I was struck by how mature, how confident this little boy was for one so young. Christophor had more dealings with the boy’s night-siblings, of course, but I had some recollection that both Patrik and Victor shared a great deal in their characters and interests. They shared knowledge, too, in the little notebooks that bulged squarely in the boy’s pockets.

‘What brings you to the fountain on a fine day like this?’ I asked.

‘You. I was waiting until you’d finished your business at the chandlers.’

‘You were spying on me?’

Patrik shook his head solemnly. ‘Observation is the greatest part of any scientific undertaking.’

‘I wasn’t aware I was of scientific interest,’ I said. I seemed unable match Patrik’s seriousness, unable to keep a sardonic edge from my voice. Though I was aware enough to realise the irony of my childishness given our respective ages.

He took a notebook from one of his pockets. ‘Yesterday you visited the painter, Marcus, but did not spend the whole day on his balcony. You returned to the inn, and met my mother’s day-sister, Rebecca. There you—’

‘You have been sp—’ I coughed. ‘You’ve been observing me very closely indeed.’

‘Not just you – we’ve been following your night-brother too,’ Patrik said.

I tried to remember Christophor’s various interactions with the Eder children, having little more than fragments and flashes of their meetings and conversations at my disposal. But the feeling that came through strongest from my night-brother was of respect: surprised at first, begrudging later, and then finally something genuine and unfettered. I wondered how he would feel about their ‘observation’ – he was the one who sought them out, not the other way around.

‘May I ask why we are of such interest?’ I said.

‘Because you are the King’s Special Inspector.’

‘Christophor is, yes.’

‘And you are assisting him,’ Patrik said plainly.

‘He might say otherwise.’

The boy looked away, as best as I could judge towards the Eder house on the valley’s slope. ‘We do our best for our siblings, don’t we, Alexsander? But it can be hard.’ He turned to me. ‘I came to show you something. Something my night-brother and Julia don’t think we should share with you.’

‘Oh?’

‘Julia doesn’t trust you, and that weighs heavily on my night-brother. But I am not so close to my day-sister. So…’ Producing a different notebook, he opened it on a marked page. It held a neat table of numbers that meant nothing to me. ‘This is the river,’ he said.

I stared, uncomprehending. But he was patient with me.

‘This column is the date.’ He tapped the leftmost set of numbers. ‘This is the time our handkerchief took to cover fifty meters. And this is the estimated water speed.’