Porter looked straight into his steely blue eyes. ‘I know how to get Katie Dartmouth out.’

He could see the man’s reaction in his face. Nutter, he was thinking. Just like the other guy. But he remained silent.

‘I can get her out.’

‘This way, please, sir,’ said the officer.

Porter could feel his chest thumping. This was his one chance to show Sandy he could amount to something. To look her in the eye without feeling ashamed of himself. He’d no more throw it away than he’d throw away his own life.

‘I’m the only man who can get through to her kidnappers,’ Porter shouted.

He could see a few of the office workers looking at him distastefully before hurrying on. None of them wanted to hear what he was saying, and none of them were looking in his direction. The five guards were slowly closing in on him, forming a tight semicircle from which there was no chance of escape.

‘This is your one chance to save her,’ said Porter. ‘I was SAS, I know something about the man who’s holding her, something we can use.’

He could feel a hand grabbing hold of his arm. The MP-5 wasn’t jabbing into his chest, but it was definitely pointed in his direction, and the expression of the man with his finger on the trigger suggested he wouldn’t hesitate to use it if he had to. They were starting to move him towards the door. Porter shrugged himself free. These goons weren’t going to listen to anyone, he reflected bitterly. Osama bin Laden could walk through the door offering to turn himself in, and they’d tell him to come back when he’d made an appointment. ‘I can walk,’ he growled.

A fresh blast of cold air struck Porter in the face, as he stepped out into the morning air. A gust of wind was blowing through him. It can take my hopes and blow them away, Porter told himself. I must have been mad to think they would listen to me.

‘Don’t come back,’ said the officer firmly.

A Jaguar was pulling up outside, and a man in a charcoal-grey suit was climbing out of the back seat. Porter recognised him at once. Sir Angus Clayton, the director general of the Firm. Porter had seen his picture in the papers he sometimes fished out of the bins he slept next to. He might even have used his mugshot as a blanket once or twice. A tall man, with a fast-disappearing head of black hair, and a face that was shallow and drawn, he looked tired even though he hadn’t started work yet. Porter was standing only a few yards away from him. If I don’t take this chance, he told himself, then I’ll never get another.

‘I can get Katie Dartmouth out for you, Sir Angus,’ he shouted.

The man looked at him. His eyes were focused, intent, as the words struck home. He was assessing Porter in an instant, scanning his face, using a lifetime of experience in the intelligence trade to make a snap judgement on whether the man might be worth listening to. He slammed the door shut on the Jaguar, and started walking towards the entrance doorway.