Singh took over, sitting down opposite the four students, getting onto their level so as to not appear intimidating.

‘First, we’d like to know when you all saw Leon last.’

‘We don’t know where he is,’ Courtney spoke up quickly. Her voice was soft, with a nasal quality to it, but her speech was clear. The detectives knew from experience that not all deaf people were fully reliant on BSL, but Forest still looked a little surprised to hear Courtney speak.

‘Don’t worry, we’ll come to that later. Think back to when you last saw him,’ Singh repeated, keeping his voice low and gentle.

A small line appeared between Courtney’s eyes as she thought. ‘Friday night, when we all went to bed. I didn’t see him in the morning.’

Same, Cassie signed.

Bradley looked at his brother. We went to bed about eleven, something like that. We didn’t see him in the morning, did we?

Kian shook his head, but didn’t add anything. I wondered how often he let Bradley speak for him.

‘Did any of you leave your rooms in the night?’

There was a pause before any of the students responded to this question, and I thought I could detect a slight flush on Cassie’s face. A movement caught my eye: Bradley’s hand snaking down to squeeze Courtney’s. This time, however, none of them looked at each other, but each in turn claimed they’d been in their rooms all night.

Singh’s next question established that they’d all been woken around seven-thirty on Saturday morning – Sasha had been in to wake the girls, and Steve the boys.

Mr Wilkinson asked us where Leon was, Kian told the detectives, his anxiety showing in the speed at which he signed. But we didn’t know, did we, Bradley? We said we didn’t know. We didn’t see him leave.

‘Okay, now let’s talk about Mr Wilkinson. When did you last see him?’ Singh asked.

‘He and Mike were talking in the kitchen when we got up,’ Courtney offered, Cassie nodding her agreement. ‘They kept asking Bradley and Kian questions. We didn’t know what was happening until Bradley told me Leon had gone.’

Bradley continued the story. When we were all up, he went out to look for Leon.

‘He didn’t come back to the cabin after that?’

All four students shook their heads.

‘Did you see anyone else outside the cabin?’ Forest asked.

There was a moment of hesitation as the four of them looked at each other again. Well, Mike went out as well, Cassie offered. He said he was going to look for Leon and Mr Wilkinson. But he came back alone.

I felt a sense of unease as a look passed between the two detectives. My head swam as a thought hit me – could Mike have done this?