‘No,’ said Gabriel. ‘Which again suggests he was taking care not to reveal links with someone or some organisation.’

Gabriel was leaning against a wooden fence near the ride exit. The park’s staff were scrubbing at the concrete on the other side of the tracks with industrial-strength disinfectant and the astringent smell of hydrogen peroxide irritated her nose.

‘One more thing, boss. The video. There’s something not right. I don’t mean the content – that’s par for the course for these people. But the way it was filmed, the language. I was racking my brains for why it rang a bell. But it’s shot for shot, prop for prop, like a pastiche of an ISIS suicide video.’

There was stunned silence.

‘You’re kidding?’

‘I’m not. Look at it objectively. All that’s missing is Fletcher holding up an AK47. And his tone, his language, it’s like he’s announcing his martyrdom.’

‘But he ran off,’ said Tennant. ‘He was a pretty shit martyr.’

‘I know, but maybe he simply bottled it? I think there’s enough here to warrant a change in tack. This isn’t just a manhunt for Fletcher, we’ve got to assume that the NRF is a serious threat, and that they could be planning further attacks.’

#

Downing Street, London

It took Tennant three minutes to walk from New Scotland Yard to the black fortress gates of Downing Street where a cheery constable waved him through. For each step of that journey along the secure, gated shortcut that ran between the Met’s HQ and the neighbouring Ministry of Defence, the implications of Gabriel’s words filled his head. If she was right, they had to assume more was to come, maybe tomorrow, next week. There was now a desperate urgency to get to the bottom of this group.

Half a dozen TV political correspondents were lounging on the pavement opposite Number Ten. The pack was conferring – making sure their lines were consistent before speaking to their news desks – and they barely registered Tennant’s presence. He lifted the black knocker and let it fall, disturbing the Downing Street cat, a self-contained creature which had outlasted the four previous PMs and which had been licking its bottom contemptuously on the doorstep, its rear end facing the journalists. A media critic, thought Tennant.

The door was opened by a security guard who ushered Tennant onto a red carpet that crossed the foyer of Number Ten and extended down the corridor leading to the PM’s office. He made his way briskly down the passage and into the anteroom with its funereal oil paintings, past the staircase adorned with pictures of ancient prime ministers and finally into the lobby outside the PM’s office where a huddle of civil servants and the head of MI5, or Thames as the agency was known in Whitehall, was waiting restlessly for the pre-COBRA briefing with the PM and Home Secretary. Tennant preferred these small, informal meetings to the full COBRA. He could be more open about operational matters away from the leak-prone junior ministers.