The two men entered one of the glass-fronted offices that spanned the back wall, turning the floor-to-ceiling window opaque at the flick of a switch inside the door. No longer able to see inside, Hawkins’ attention returned to her wider surroundings. She could see no further activity from here in the waiting area, but from beyond the adjacent partition came a subdued bustle that belied a large team working in silent coordination. In fact, since she had stepped out of the lift, there had been a solemn efficiency about the fourth floor of 8-10 Broadway – a no-nonsense ethic that, given the nature of their work, was oddly reassuring.

Her bag began to bleat quietly, and she bent after her mobile to silence the alarm that reminded her they were running out of time to charge the man she’d arrested the previous afternoon. Thanks to Chris’s diligence, they now had a name for the watcher, but without fresh evidence tying him to their investigation, what she now knew of his past counted for nothing.

In eight hours, he walked.

Hence her visit to New Scotland Yard.

Hawkins found her phone at last, straightening as she pulled it free, intending to check her messages.

To find she had company.

Standing beside her was a fortress of a man with flecks of grey in short charcoal hair, clearly lighter on his feet than she would have believed; his right hand extended. ‘Superintendent Andy Whiting. You must be Antonia.’

‘Yes.’ She stood as they shook.

Politely he asked, ‘Could I see your warrant card?’

‘Of course.’ She dug it out, handed it over.

Whiting studied her identification with dark, alert eyes before passing it back. ‘Sorry to keep you waiting, Chief Inspector. Welcome to SO15.’

He turned and led Hawkins around the partition, on which a modest plaque said Counter Terrorism Command, and through the industrious hub of his team, smartly dressed workers moving around them, holding efficient conversations in small groups, none loud enough to reveal their content.

Whiting didn’t speak again until the door had closed behind them in a nicely appointed office on the perimeter of the main space. New carpet, and the residual scent of fresh paint.

Hawkins took one of the comfortable seats in front of the wide oak desk, placing her coffee down on its surface.

‘Apologies if the atmosphere’s a little tense out there.’ Whiting moved around the desk and sat opposite her. ‘It makes some visitors uncomfortable, but when you’re dealing with the threat of terrorism on every level from local radicalization to international extremism, it becomes second nature.’ He leaned forwards. ‘Anyway, how can I help?’