Still, it was natural to make assumptions. And so somewhere in the back of Bull’s mind he had been expecting . . . what?

Something more, he admitted to himself. Something more.

The single most significant terrorist attack in British history. Five hundred and thirty-four deaths. Carried out – if Mansour’s confession was accurate – by a man whose most significant feature was how very ordinary he looked.

Bull knew all the clichés about books and covers. But he also knew other clichés, too. Ones about going with his gut. And right now his gut was not quite buying this.

Mansour had been escorted into the room by a stocky police constable. A rugby player, by the look of him. There were a few in every station, Bull knew. A hard sport, it helped with the more physical aspects of the job.

And shoulders that wide helped keep suspects in check.

You run, you run through me, he thought. That’s the idea.

It was an unnecessary message to sell to Mansour. He would not be running anywhere. After a lifetime as an investigator, Bull could tell a broken man at a glance.

Which only fuelled his uncertainty.

He gestured to the constable to remove Mansour’s cuffs. The man did as instructed, then positioned himself between Mansour and the door.

‘Outside, please,’ Bull instructed.

The constable looked confused.

‘Sir? Are you . . .’

‘I’m sure,’ Bull interrupted. ‘Mr Mansour and I are going to chat alone.’

Bull’s eyes remained on Mansour as the officer did as ordered. They stayed there, too, as Bull reached out and pressed the record button on the sleek audio device that sat on the small table between them. A discreet replacement for the analogue tape decks Bull had been using for decades. Progress of sorts, he figured.

The fixed, unbroken stare was a practised technique. Designed to show the suspect who was in charge. That he could not be intimidated. It was wasted on Mansour. He hadn’t lifted his head once to meet Bull’s eyes.

It was, like so much else, confusing.

Why the hell confess? Bull found himself thinking, and not for the first time. Why confess and then pull this shit?

Bull reached out to a more discreet switch, activating yet more modern equipment: the interview room’s video recording system. From that moment, everything that occurred within the room would be recorded both visually and audibly.

Still Bull had not blinked.

‘Nizar, you understand that I am about to ask you some questions about what happened today. From what I’ve been told about your conduct earlier I have no doubt that you speak and understand the English language. Is that correct?’

There was no response.

Bull continued.

‘Because before we begin I need you to confirm for me that you know you’re entitled to have a lawyer to advise you during this interview? You have been told that, haven’t you?’

Bull looked carefully at Mansour as he spoke. It was essential to show that the suspect understood, because what Mansour said in reply could be all important. The last thing Bull wanted was for some smart-arse lawyer in a horsehair wig to suppress that evidence within a maze of technicalities.