Can you let me in? I signed through the glass, and Mike nodded. By the time I walked back round to the front door, he was holding it open for me.

‘Sorry,’ he said. ‘I heard the bell but I thought it was one of the students. They’re not meant to come back here during lesson time.’

‘It’s okay. I was looking for Sasha, actually.’ It felt strange to be talking so civilly to Mike, and I was surprised to find it wasn’t as difficult as I would have expected.

‘Sure, she’s in there,’ he said, with a nod towards the common room.

When I walked through, the three of us stood there awkwardly for a moment. Sasha and Mike had obviously been in the middle of a conversation that they didn’t want to continue in front of me, but also I didn’t really want to involve Mike in my questions about Joe, whoever he was. Sasha must have realised this, because she gave Mike a pointed look and he made his excuses and shuffled off up the stairs with a swift backward glance.

How can I help you? Sasha asked with a taut smile. I noticed the set of her jaw and shoulders looked very tense, and my curiosity was piqued. Had she and Mike been arguing? And if so, what about?

I wanted to ask you if there’s a student called Joe? Either current or past.

Joe? Sasha’s eyes widened for a moment, before her expression settled into a frown. Why do you ask?

Yesterday, the four students who were on the trip were talking about someone called Joe, about whether or not they could trust him, and if he had anything to do with what happened on Saturday. I wondered if it was someone they knew from school.

Sasha seemed to be taking in what I’d told her, before she shook her head slowly. No, I don’t know of a student called Joe. But I haven’t been working with the school for as long as someone like Liz, so perhaps you should ask her. I was just on my way over to see her actually. Why don’t you come with me?

She glanced over her shoulder in the direction of the stairs, before guiding me towards the door.

Do you need to finish your conversation with Mike? I asked, picking up on the tension in her body language.

Sasha laughed but there wasn’t much amusement in her tone, and I wondered what they’d been discussing. She was probably wondering how long I’d been there when they noticed me, but I hadn’t seen what they’d been signing to each other.