She called the dog over and began petting him. ‘A guy at college told me about LfA. John’s his name. I think he’s a mate of Riad and Ali’s. He said that LfA organises flash mobs and protests and sometimes you get food or a bit of cash.’ Something zipped across her face. ‘They post the date and venue on the forum, and say whether it’s going to be morning, afternoon or evening. You go on the website and enter your details, and they WhatsApp or text the location and time on the day.’

‘Did you know what the events were about?’ I asked.

‘He did tell us but, to be honest, I just thought it would be a good way to make a bit of cash and have a laugh.’

‘Can you remember who you communicated with?’

‘It’s always a guy called Frazer who posts on the forum, then someone else gets in contact.’ She gave a sheepish smile and stroked the dog’s ears.

‘What were you told you were going to do?’

‘To dance in the street for half an hour.’ She laughed and fiddled with her top-knot.

Something felt off. I thought carefully about what to say. ‘Were any other elements described?’

She frowned. Confused. ‘He said something about gentrification, but it went right over my head. We were just there for a laugh.’

‘Anything criminal?’

She shook her head furiously. ‘God, no. If I got involved in anything like that my dad would kill me. It was just a laugh. When that fire broke out, we were all shocked.’ She looked from me to Dan.

‘Who else did you know there?’

‘Just Riad. He’s my boyfriend. His younger brother, Ali, and the guy called John that I told you about. I don’t really know him. I didn’t know half the people there. I recognised a few faces from other flash mobs, but no-one by name.’

‘Is John from New City College too?’

‘Yeah. I think Riad said he’s doing one of the new BTECs. Digital Technologies or something. He’s around fifteen.’ She screwed up her nose.

‘How do you know Riad and Ali?’

‘We met doing the climbing wall at the youth club.’ Her eyes danced with excitement. ‘It’s lots of fun. Have you ever done it?’ She giggled nervously.

‘Have you wondered whether the flash mob and the fire were linked?’

Her hands went to her face. ‘Oh my God, you don’t think . . . ?’

I studied her body language. Was she a good actress or genuinely naïve? ‘We think it’s very possible.’

‘Please don’t tell my dad that. He’ll kill me.’

‘Sophie, please be honest with us. This is important. Did anyone at the flash mob mention the fire?’