There was a pause as I saw this sinking in, some of the students realising the seriousness of the situation. Was there someone in the school that posed a risk to these students, or had that risk been eliminated now Steve Wilkinson was dead? A thought occurred to me, and I wondered if Singh had been looking into the idea of the murderer being some sort of vigilante, trying to keep the students safe from a predator.

There were no more questions, and Singh dismissed them. As the teachers led their students out of the hall, Liz Marcek came over.

I think that was a little unnecessary, suggesting there might be someone close to them who wants to hurt them. If you’ve scared any of my students, I will not be happy. Her jaw was set in a solid line as she glared at Singh.

‘I’d rather scare them into taking extra precautions than let them think online safety isn’t important, and I want them to realise they can come to us with anything they’ve witnessed or experienced in school that has made them uncomfortable. I’m sorry if that doesn’t quite go along with your ideas, Miss Marcek, but my priority is the safety of these children.’

When Singh got angry, he didn’t shout. He spoke clearly and calmly, and the only indicator that his emotions were high was the flashing of his eyes. Liz held his gaze for a moment, then nodded.

‘I checked the list of Steve’s personal effects after Cassie’s claim about finding a key,’ Singh continued. ‘There were two bunches of keys found in his room in the cabin, one of which held his house and car keys. I assume the others are for the school.’

He showed Liz a photo of a set of keys and she pointed to one of them. That’s his office key, so it’s definitely accounted for. I don’t understand where Cassie got one from.

She walked off, looking puzzled, and I knew how she felt. I had been sure that Cassie had taken Steve’s key, but it was accounted for. Maybe this mysterious friend she had talked about had given it to her?

Singh looked at me and shook his head. ‘I probably shouldn’t have said that, about keeping the kids safe, but I didn’t like her insinuation. I believe in protecting the children from the gory details of this crime, but these kids aren’t going to respect us, and therefore talk to us, unless we’re honest with them.’

He began to pack up the laptop that had displayed the presentation, and Sasha came over to speak to me.

I can’t believe this is happening. Her face was drawn and there were dark circles under her eyes. Liz called me yesterday to tell me what the police had discovered about Steve. How did I miss something like this?