All your cases, I thought, do not belong to us.

So I did what I always did in these situations, and asked myself what Lesley would do – apart from taser me in the back and betray me to the Faceless Man, that is. And what she would do is say – Start with the action list – duh!

A modern major investigation runs off HOLMES II, which is a great big computerised mincing machine into which your investigating officers shovel information and turn the handle in the hope that something edible, or at least admissible in court, will emerge from the other end. In order to keep the machine fed, senior officers assign their junior officers ‘actions’ – interviewing Hannah’s and Nicole’s teachers is an ‘action’, as is checking the family phone records against the numbers of known sex offenders. The police never saw a noun they didn’t want to turn into a verb, so it quickly became ‘to action’, as in you action me to undertake a Falcon assessment, I action a Falcon assessment, a Falcon assessment has been actioned and we all action in a yellow submarine, a yellow submarine, a yellow submarine.

Thus, to review a major inquiry is to review the list of ‘actions’, and their consequences, in the hope that you’ll spot something that thirty-odd highly trained and experienced detectives didn’t. I sat down and made a note in my notebook – Commence Falcon assessment with review of action list – and dated it.

It was lunchtime on day three, Hannah and Nicole had been missing for over fifty hours.

Day One – 09:22 – first and only 999 call – caller identified himself as Derek Lacey.

I didn’t listen to the sound file, but even from the transcript you can sense him struggling to maintain control. He’d obviously taken a moment to marshal his arguments in the fear that the police wouldn’t take him seriously, because he listed off Nicole’s and Hannah’s ages, the fact that they had left their bedrooms some time during the night, and that none of their friends or relatives had seen them. And he’d clearly impressed the Force Duty Inspector at the Worcester control centre, because he in turn had sent all of available D-shift directly to Rushpool, headed by PS Robert Collington.

Team D had a TOA (time of arrival) of 09:37 at which point Edmondson, as geographic commander, had been informed and had chosen to take ownership of the operation.