‘My big brother is deaf,’ Saul told me. ‘My parents learnt to sign when he was a baby, so when I was born three years later we all used it at home. He has hearing aids and he learnt to speak pretty well, so our parents gradually stopped the signing, but Isaac and I kept it up. We had a secret language that nobody else knew, it was amazing.’ He grinned at me. ‘I think it was only natural that I’d end up teaching deaf students.’

‘Do you just teach IT?’ I asked. ‘Or do you have another subject as well?’

‘No, just IT, but I also manage the network, handle all the hardware and software, and so on. When I’m not teaching, I’m checking the tablets are updated, or sorting out the projector for an interactive whiteboard, or more often than not resetting a password when someone’s forgotten it.’

‘Sounds busy.’

‘I can’t complain, really. I enjoy it. The only problem is the lack of money for new equipment, so I have to make sure we keep everything in good working order.’

As Saul and I chatted, I watched some of the students interacting. The three students I didn’t know were all sitting together, with Bradley and Courtney next to each other on the opposite side of the room. Whenever I looked up, they were signing to each other under the table, but as soon as they saw me looking in their direction they stopped. Under the desk, I could see Courtney’s foot hooked around Bradley’s ankle.

‘It’s a bad business, this with Leon and Steve,’ Saul muttered. ‘I’m worried about how the kids are taking it.’

I was about to ask another question when the door opened and Liz Marcek walked in. All the students sat up a little straighter, but she was more interested in my presence.

Paige. Is there something wrong? Her lips were pursed in irritation, presumably that I’d been wandering around the school without her knowledge.

No, I was just talking to Saul about the school, I replied.

The police don’t need her at the moment, so I said she could observe my class, get to know the school a bit better, Saul chipped in, and I flashed him a quick smile.

Well, if you’re interested in a tour, I’m happy to oblige, Liz replied, holding open the door and giving me a wide smile that didn’t quite reach her eyes. Recognising that I’d been dismissed, I walked out into the corridor and she followed me.

This was your sister’s school, I believe. Have you never looked round?

No, I’d only been in the main hall before this week, I replied, wondering who had told her about Anna.

Then follow me. She marched off, her back ramrod straight and her nose in the air.