Of course, it was possible that no such person existed. The internet created so many opportunities for anonymity and un-traceability. I needed to speak to Jackie. Get her input. ‘It’s time to put out another public appeal. Get onto the media liaison officer and Megan in PR right away. We need to get the message out to everyone who saw the fire start that their eyewitness accounts are vital.’

I left the Portakabin with my mind racing.

As I stood facing the debris from the fire, I developed a creeping feeling that someone was watching me from behind. Just as I wheeled round, a net curtain dropped into place in one of the windows above Rosa’s shop, and a light was clearly on in the room beyond. Then a hand drew both curtains. That was strange. Burglars didn’t tend to put lights on if they could be seen through net curtains. And if Rosa had gone to Agnieszka’s, who was in the flat above the shop?

Maya, 1.30 p.m.

Maya, 1.30 p.m.

‘She’s not at Tomasz’s either?’ I was on the phone to Rosa’s daughter. ‘I think I know where she is in that case.’ I told Agnieszka about the light I’d seen in her mother’s flat. ‘I’ll give her a quick knock and make sure she’s OK.’

When Rosa appeared at the shop door a few minutes later, she was back in her own clothes and had managed a thin smear of lipstick. ‘Oh, hello, Inspector.’

‘For some reason you don’t seem surprised to see me,’ I said, teasing her.

‘I know they mean well but I don’t need nurse-maiding. I’m looking forward to sleeping in my own bed tonight.’ Her tone was triumphant. ‘That’s if my daughter doesn’t arrive in a few minutes and cart me off. I’m guessing you told her I was here?’

‘I saw the light on and had to call her to ask if you were there. Everything alright up there?’

‘Perfectly, thank you.’

Her determination made me chuckle. ‘You take care now. OK?’

I was soon on Ben Jonson Road, heading back to the office. The traffic was at a standstill while a bulldozer and a bus tried to pass each other in a narrow street with cars parked on either side.

My phone rang. I switched the loudspeaker on. ‘Hi, Doc. What’s the news from the lab?’

‘As we suspected, both bodies were badly burned. I’ve taken dental samples and sent the woman’s for fast-track analysis. If she has records, those should enable an ID. The forensic scientists aren’t sure if they’ll be able to extract enough DNA strands from the samples I took. She had a lean frame and there’s very little tissue on her bones. We’ll have to keep our fingers crossed. It might just be family details, I’m afraid.’