‘We came over to talk to your experts,’ said Caroline, who made it clear that she’d been dragged over as reluctantly as any child to an art gallery. Despite tea and cakes Caroline thought she’d just about reached peak boredom when Professor Postmartin was called away.

‘You’re not interested in The Third Principia?’ I asked.

‘It’s not going to have anything about aerodynamics in it,’ she said. ‘Is it?’

‘Aerodynamics?’ asked Guleed.

‘Caroline wants to fly,’ I said.

‘Does she know about your swan dive off the top of Skygarden Tower?’ asked Guleed.

She does now, I thought.

‘The one that was blown up?’ said Caroline.

‘As it came down,’ said Guleed, who wasn’t making any friends just then.

I busily rooted around in the equipment rack for a couple of screamers while Caroline fished for information. Had I actually been flying, or gliding, or otherwise retarding my fall through the use of magic and if so – how?

‘Retarding,’ I said while I checked that the screamers were working. ‘Only it was the Faceless Man doing it, not me.’ I handed the screamer to Guleed and showed her how to use it.

Caroline wanted to know whether I’d seen how the Faceless Man was controlling his descent, and I remembered the tower falling, the screaming, the smell of brick dust and the whole wide world rushing up to smack me in the face.

‘I was a bit distracted at the time,’ I said. ‘But he had to concentrate to maintain it.’

‘So what happened to Dr Walid and Lady Helena?’ said Guleed who always liked to keep things moving along.

‘After the professor rushed off, your pair of mad path ologists asked my mum whether she’d like to see their unparalleled collection of horrible things,’ said Caroline. She explained that she hadn’t really fancied it herself. She would have done a bit of exploring around the Folly, only Molly kept on following her, so she came into the yard and found the tech cave.

‘It wasn’t locked?’ I said.

‘No,’ she said, and smiled innocently. ‘Was it supposed to be?’

‘Generally I keep it locked.’

I chivvied her out and she ended up helping me and Guleed carry the boxes of books up to the library.

‘Anything in these for Mum?’ asked Caroline.

‘She can take that up with the Professor,’ I said. But that’s when I decided to take Caroline with us to check Christina Chorley’s room.

*

It was all going perfectly fine until I noticed Martin Chorley’s watch. After that, as Nightingale might say, it all rather went downhill.