Neville saw the policeman as he reached the bottom of the steps.
The motorcycle officer was about the same height as Neville, his white helmet gleaming beneath the fluorescents in the underground car park.
Neville slowed his pace, watching as the policeman walked slowly around the Harley Davidson, his own bike parked close by.
The air reeked of diesel fumes and oil. Black cabs were dropping off passengers then heading down the ramp to collect more in this underground area of Euston.
Neville had left the bike there, not expecting any trouble, not expecting anyone to find it until he was ready to leave.
He took another step towards the Harley, watching as the cycle cop continued walking around, inspecting.
When he turned to face Neville, the ex-para could see that the uniformed man was in his early twenties.
He flipped up his visor as Neville approached.
'Is this your bike, sir?' the policeman asked, running appraising eyes over the leather-clad newcomer. 'You realise it's parked illegally?'
Did he know? Was this a ruse?
'Have you any identification on you?' the uniformed man wanted to know.
Neville reached for the zip of his jacket, aware of the bulky weight of the. 459 and the. 357 beneath each arm.
He was looking fixedly at the young policeman.
Two businessmen who had just alighted from one of the taxis passed by, glancing disinterestedly at the tableau.
'Why did you park here?' the officer continued.
Neville eased the jacket open slightly.
The policeman's radio crackled and he pulled it from his belt, flicked it to 'Receive'.
Neville stood gazing at him.
The policeman nodded as he heard what was being said to him by the voice at the other end.
Nodded.
Neville kept his gaze fixed on the uniformed man.
He knows.
The policeman looked straight at him.
For interminable seconds it was as if both men had frozen.
He fucking knows.
A woman struggled from a cab, the driver helping her with her massive suitcase. Both glanced at the motorcyclists nearby.
From above, Neville heard some words being called urgently over the station Tannoy but his eyes were still riveted on the policeman.
'Your ID, sir,' the policeman said, the radio still pressed to his ear.
Neville slid his right hand inside his jacket and pulled the automatic free.
He saw the look of surprise on the young policeman's face as the pistol was hefted before him, the barrel yawning wide.
Neville fired.
The sound was amplified by the enclosed concrete space and the gunshots exploded like a sonic blast, deafening everyone in the confined area.
The woman with the suitcase screamed, her cries drowned out by the blasts.
The first bullet hit the policeman in the left shoulder, tore through and erupted from his back, cracking a portion of his scapula, taking gobbets of flesh, bone and material with it.
It was quickly followed by a second, which thudded into his stomach, doubling him over; fingers clutching at the wound, one slipping inside the hole as blood poured freely down his body.
He dropped to his knees, his visor falling forward and Neville could see the uniformed man staring at him almost in bewilderment through the Perspex.
He fired one shot through it.
The clear material shattered, the bullet powering into the policeman's cheek, punching his lower jaw, blasting several teeth free.
Blood seemed to fill the helmet and he fell on to what was left of his face.
The woman was still screaming.
The taxi driver had run back and leaped behind the wheel.
Other cabs in the drop-off area were accelerating towards the ramp, anxious to escape, one even tried reversing up it.
Neville swung his leg over the Harley's seat, started the engine and twisted the throttle.
The bike screamed on to the road, skidding slightly, back wheel spinning.
The woman had stopped screaming now, and was standing motionless, gazing down at the body of the policeman, her eyes bulging wide in their sockets as his spreading blood reached her shoes.
A taxi driver jumped from his cab and ran up the ramp into the street, the breath rasping in his lungs, eyes searching the clogged traffic.
He was the first to spot the approaching police car.
By now others had heard the sirens.