‘I’m giving you a week on account of the inalienable laws of hospitality,’ he said. ‘Then I’m going to consider it an open field – okay?’

It seemed a safe bet that something else would have caught Zach’s attention by then. ‘Yeah,’ I said. ‘Whatever.’

Zach slapped his six-pack and looked around. ‘Now that we’re up,’ he said. ‘What do we do about breakfast?’

‘In this establishment,’ I said. ‘We dress for breakfast.’

Nightingale certainly did, his only concession to informality being that he left the top button of his shirt undone and draped his blazer over the back of his chair. He was addressing his toast and marmalade when I showed Zach, currently sweet-smelling and freshly laundered thanks to Molly, into the breakfast room. Nightingale gave me a quizzical look as Zach fell upon the line of silver salvers with cries of glee and started piling up his plate with kippers, scrambled egg, kedgeree, mushrooms, tomatoes, fried bread and devilled kidneys. I sat down and started pouring coffee.

‘Zachary Palmer,’ I said.

‘The late James Gallagher’s lodger,’ said Nightingale. ‘Lesley filled me in with the case history last night during the rugby.’

‘He has a secret or so he says,’ I said.

‘Let me guess,’ said Nightingale. ‘Demi-fae?’

‘If that means half fairy – then yeah,’ I said. ‘How did you know?’

Nightingale paused for a bite of toast. ‘I think I knew his father,’ he said. ‘Or possibly his grandfather – it’s never easy to tell with fae.’

‘You haven’t taught me about fae yet,’ I said. ‘What are they exactly?’

‘They’re not anything exactly,’ said Nightingale. ‘Fae is just a term like foreigner or barbarian, it basically means people that are not entirely human.’

I glanced over at where Zach had given up trying to pile everything on one plate and had resorted to using two. Toby had sidled up to sit within easy sausage-catching range, just in case.

‘Like the Rivers?’ I asked.

‘Less powerful,’ said Nightingale. ‘But more independent. Father Thames could probably flood Oxford if he wanted to, but it would never occur to him to interfere with the natural order to that extent. Fae are capricious, mischievous but no more dangerous than a common cutpurse.’ That last sounded suspiciously like a quote. ‘They’re more frequent in the country than the city.’