‘Oh, it’s going to be one of those jobs,’ said Carey when I settled in beside him. ‘Is it too late to put in for a holiday?’

I told him it was, but if he was lucky Guleed would do all the heavy lifting.

‘So long as I don’t have to deal with any more weird cars,’ he said.

The job had acquired an operational name, MARIGOLD, and a quick call to the case manager in the Inside Inquiry Office got me access to HOLMES. I entered the results of my preliminary search of Olivia’s bedroom and downloaded the pictures I’d taken of the collage on the wall. Then I went hunting to see if anyone had developed a definitive list of the kids who’d been at the party, to see if I could match them up. I did that until Carey pointed out that the current list was on the whiteboard – along with photos. I matched up Albertina Pryce to one of the pictures in Olivia’s collage but none of the others. I asked Carey whether this was the confirmed party list, but he said they were still waiting on statements.

Down the corridor in an interview room Olivia, now sitting next to a solicitor with a properly expensive suit and a suitably belligerent Scouse accent, had sensibly decided to keep her mouth shut. Guleed was pissed off, because not only had the preliminary search of the Tyburns’ house not turned up anything useful, but of the six separate sets of prints lifted from the pill packets none had matched Olivia’s. Nor, in fact, had any of the prints recovered from the flat at One Hyde Park. Guleed wanted to know if Tyburn could magic away fingerprints, but I said probably not without wiping everything else. She asked me to check with Nightingale, and I said I was sure because I’d made a point of coming up with a list of modern forensic techniques and then going through them one by one to see if Nightingale could counter them.

‘Did anything work?’ asked Guleed.

‘So far nothing,’ I said. ‘You can burn the top surfaces off a scene, but it’s pretty obvious that you’ve done it.’

‘I can imagine,’ said Guleed, who’d once seen me roast a duck by accident.