By the time she was at home in her kitchen, mug of mint tea in hand, trying hard not to wake Ray upstairs, her head was a little clearer, and her conviction that Abu Mujahid was back in the UK a little stronger.

DAY 6

Monday

CTOC, St Pancras, London

Gabriel had once been told at a professional development course on public speaking that the best way to silence a room was to stand still holding her arms out wide, palms down, and then to gradually lower her arms. The most important thing Gabriel had learnt that day was that much of the advice shared at professional development courses was nonsense.

‘Shut up, please,’ she bellowed. The babble of sixty people squeezed into the ops room simmered down quickly. Gabriel could sense the crackling in the air, but felt numbness where she should be feeling energised. The media was still sniping at her over the Pall Mall fiasco and there was still nothing more on Abu Mujahid. He had made no obvious contact with his family, the lorry had vanished and so had four of the six migrants pulled over by Sussex Police. The remaining two were due to be interviewed that afternoon.

‘This week has been like none I can remember,’ she said, summoning an enthusiasm she did not feel. ‘You’ve given up your leave, your home lives and shown a level of dedication that I’m not surprised to see, but I am gratified to see, nonetheless. And I’m asking you to continue.

‘We are in the firing line, but we’re used to that. And the best answer to our critics is to do our job well. So we’ll start with Pall Mall and the two missing killers. Facial recognition software has come up with a longlist – some two thousand-odd faces from driver’s licences and passports. The video unit’s whittling them down now by hand and should have something by first thing tomorrow.

‘Even better news is the familial DNA results from the petrol bomb fragments are in. We’ve got a reasonably close match between the DNA extract and the DNA of a forty-eight-year-old-male called Tony Roberts. We know he wasn’t involved in Saturday’s attack because he’s currently serving time in Wakefield for seven sexual assaults including a serious assault on a child. However, his family tree is large and complex, and we’ve narrowed our suspect to one of fourteen adult males closely related to Mr Roberts. It’s likely to be a sibling, cousin, second cousin, uncle or nephew. The family are spread over South London, Essex, Sussex and Devon. Surnames are likely to be Roberts, Clark, Houghton or Clifton.’

There was whispering at the back at this. The DNA results had not been announced to the team.

‘We need covert DNA from all fourteen family members,’ Gabriel continued. ‘We haven’t got the bodies to go after all of them at once, so we go for three or four samples a day.

‘At the same time, we use old-fashioned police work on these fourteen suspects – we need to know where the suspects are right now, and where they were Friday night and Saturday morning. We need to know who is too fat, too ill or too much on holiday, or in prison, to have been one of these men.’ She waved at the screen, which displayed the CCTV grab from the hotel.