‘Something’s up. We’ve not moved for five minutes,’ said his companion in the passenger seat. ‘Can we put the lights on and jump the queue?’

‘Maybe,’ said Glenister. The siren would draw attention to them – and could attract a police car or bike. The last thing they wanted was their own police escort taking them to the park, but it might get them out of this hole.

The siren was operated by pressing the vehicle’s horn. A toggle switch turned it from the normal ‘blues and twos’ two-note wail to the more urgent ‘woop-woop’. But was it worth the gamble? Sod it. He flicked on the blue light and the siren and checked the right-hand side mirror. What the hell was that? For a second, the mirror had flickered dark, as if something had temporarily blocked the view. And then the mirror and door swung open as he heard a yell above the wail of the siren.

‘Police! Hands on your head. Now. Get out of the seat.’

A strong hand on his shoulder twisted him down and out of the ambulance. Glenister fell a couple feet onto the tarmac, the impact sending a jarring pain through his left leg.

His head was pressed against the road, and he could see three men in uniform around him. Where the hell had they come from? Outside the cab, the siren scream was blocking out all other sounds. The road surface was cold on his cheek. Looking underneath the ambulance, he could see a body lying on the road outside the passenger door.

Glenister felt the metal of the cuffs on his wrists and then his body being lifted round. He stared up at the face of a young officer, whose eyes widened. The policeman reached for his radio. Another officer reached into the cab and pressed the horn to turn off the siren. There was a brief parp of the horn and then silence, apart from the Barnsley accent of the young officer, who spoke into his radio.

‘Driver and ambulance are secure, scene is secure, repeat secure,’ he spoke urgently. He looked down again at the handcuffed man on the ground beneath him. ‘And, sarge, you’re going to like this. The driver has been identified as the suspect wanted in the Pall Mall bombings. He’s Douglas Glenister.’

#

CTOC, St Pancras, London

Tennant cleared his throat and loosened his tie, a crimson paisley design, which Gabriel reckoned must have been fashionable a decade ago. He had come from COBRA, and judging from his buoyant mood, it had gone well.

‘First up, bloody well done, the lot of you,’ he said to the officers stood around the conference room. ‘I know you’ve had a crazy ten days, and you’ve had no sleep, no rest and no showers by the look of some of you.’ There was a ripple of laughter. ‘Forensics played a blinder with the DNA from the petrol bomb fragments, as did the teams who found Houghton.’

He banged the desk with his palm, triggering raucous applause. Gabriel forced a smile.