Courtney is obsessed with social media, documenting every moment of her free time, the social worker continued. We’ve had to do a lot of work with her to stop her giving out her personal details, but she still doesn’t really understand the dangers of talking to hundreds of strangers online. We monitor her social media, but she’s old enough to have accounts so the school only take her phone away as a punishment if she’s done something particularly risky.

‘And Cassie?’

Cassie can sometimes be a bit full-on. She has some learning difficulties, and she’s very immature for her age. The most challenging aspect is the fact that she has no idea of her own limitations – she thinks she’s very mature and very clever. I love the kids to have confidence in themselves, but if she had a better understanding of what she struggles with, she’d be able to work on strategies to counteract them and ways to get support. As it is, she insists she doesn’t need any help, she’ll manage perfectly well when she leaves school, she’ll be able to get a well-paid job, live alone and be completely independent, when in reality she’ll require a lot of support to guide her on the way to independent living. As for her social skills, sometimes she latches on to one of the other students, declares them to be her best friend and won’t leave them alone. Some of them have been teasing her recently, saying she has an imaginary friend.

Singh and Forest listened carefully as I interpreted, then went back through to speak to the four students. While Sasha and the detectives had been talking, the students had closed in and formed a tight group, signing to each other but keeping their hands low so we couldn’t see. I tried a subtle glance over through the doorway, but they were keeping their conversation well concealed. When the teenagers saw the detectives come back into the room they stopped their conversation and turned to look at them expectantly. Bradley shuffled further forwards beside his brother, almost shielding Kian from view. There was no sign of Liz or Mike.

Forest gave all the students a serious look. ‘I understand this is very difficult for you, especially with the news you’ve just received, but there are some questions we need to ask you. I want all of you to think carefully and give us truthful answers. If you think something isn’t important, tell us anyway, because it might be more important than you realise.’

Kian’s eyes widened as I signed this speech; Courtney and Bradley looked at each other, worry lining their young faces, but Cassie didn’t seem to react at all, sitting back with a little smile on her face. Was there something she knew, or did she not understand the seriousness of the situation?