But he'd been noticed elsewhere also, the approaches cleverly disguised: simple requests for legal opinions relating to Islamic matters. Eventually, he discovered that, in effect, he'd been working for Al Qaeda without knowing it-and then he'd realized he didn't mind; in fact that he welcomed the idea. Really, an opportunity to serve the cause was what he'd been looking for all his life. His own experience of the law, the courts, the legal system, the behaviours of the kind of people involved-they'd all taught him a great deal about human nature. He knew what made people tick, how to handle them, and most important of all, what made people afraid.

To run the London operation for Al Qaeda required brains and organizing ability. When it came to necessary violence, he only had to make a call to bring in whoever was best for the job. An inner circle of twenty stood ready to act.

The beauty of it was that not one of them knew Hassan-they connected by encrypted mobiles only. Shah remained just a voice on the phone: the Preacher.

Yes, it all worked extremely well.

'Let's see what we can do about this,' he murmured softly, and he made a call.

Selim Lancy was the result of a mixed marriage. His father, a sailor, had insisted he be baptized Samuel, then gone back to sea, never to return. So his mother had made it Selim, the Muslim equivalent, and raised him in the faith. He never tried to pretend he wasn't Muslim, and was particularly handy with his fists when he joined the army, 3 Para, where he endured three hard years in Iraq and Afghanistan, rising to the rank of Corporal. His service ended with one bullet through his left side and another in the right thigh.

He passed through the rehabilitation centre, where doctors put him together very nicely, but the army decided that enough was enough and he was discharged.

He returned home, and moved in with his mother, who was still fit and well at first, then started to attend the mosque again. He was surprised at the respect everyone gave him, and then realized why-when overtures were made suggesting that, as a good Muslim, he could serve Al Qaeda well. The idea appealed to him, just for the hell of it; for the truth was, he was anything but a good Muslim.

He made a living as a hired driver now. Sitting behind the wheel of a silver Mercedes, handsome enough in a dark blue suit and regimental tie, he was eating a chicken sandwich when his special mobile sounded.

'Where are you?' Shah asked.

'Oh, it's you, boss. I'm at the back of Harrods, waiting for a customer. I'm sitting behind the wheel of my new car-a second-hand Mercedes. My compensation money from the army finally came through.'

'Well, that's nice for you,' Shah told him.

'I haven't heard from you for a while. Is this a business call?'

'You could say that. I want you to check on a man called Selim Malik. He's an art dealer with a place in Shepherd Market.'

'What's he done?'

'He could be showing an unhealthy interest in rumours of British Muslims serving with the Taliban in Afghanistan.'

'They're not bleeding rumours, they're facts, boss. I should know. I probably killed a few of them over there.'

'That isn't the point. I want to know if he's actively investigating these stories. Check with other Muslims in the market; see what you can find out. No rough stuff. He's precious cargo.'

'Why's that, boss?'

'He knows things and he's got a friend named Daniel Holley, who's a killer of the first order. He may look Malik up. If he does, you must let me know at once. I've found a security photo of Holley. You'll find it on line now.'

Lancy thumbed away at his mobile and Holley appeared. 'He doesn't look much to me, boss.'

'Don't go by looks, idiot. Holley's a nihilist. That's someone who believes nothing has any value and so he kills without a second of regret. That includes you.'

'I'll bear it in mind. When do you want this?'

'A couple of days. Do what you can.'

Shah hung up. Now, he thought, what to do about Shamrock. He'd been shocked to hear the name from Hakim. He checked his watch. The stupid bastard was still up there at thirty thousand feet for at least another couple of hours. Better to wait and try to contact him at the Talbot office. He got up from the bench and walked quickly across the campus towards the university buildings.

At that same moment, Shamrock was sitting in the first-class compartment of a British Airways jumbo-jet flight from Cairo. His name was Justin Talbot. He was forty-five and looked younger, favoured dark cropped hair and a slight stubble to the chin, the fashion of the moment. He wore jeans, a light open-necked khaki shirt and a dark blue linen jacket. His face was heavily tanned, as if he'd been out in the sun a lot, which he had, and had an aristocratic look to it.

Members of the cabin crew had earlier noted that his English had a public school edge to it, and he spoke with a cynical good humour that they'd found as intriguing as the fact that he was described on the passenger list as Major Talbot.

One of the girls approached and said, 'It always gets boring with so few passengers. Not much to do.'

'Nobody's got any money at the moment. You're lucky to have any passengers.'

She smiled. 'I suppose you're right. We'll be landing in an hour or so. You'll be glad to stretch your legs, I bet. It's a long trip, Cairo to London.'

'Actually, I started in Peshawar yesterday. Stopped off in Cairo on business, then joined you.'

'Pakistan! I hear it's bad on the North-West Frontier these days. Are you in the army, Major?'

'Not any more. Twenty-odd years was enough. Grenadier Guards. I did a certain amount in Northern Ireland, both Gulf wars, Bosnia and Kosovo, then two tours in Afghanistan. I was lucky to get out of that in one piece. When I was shot in the right shoulder,' he smiled, 'I decided that was it and took my papers.'

He didn't mention the Military Cross he'd earned in Afghanistan, and the years with the SAS and the Army Air Corps. The young woman nodded seriously. 'You've done your bit, if you ask me. What do you do now?'

'I work for the family firm, Talbot International. We sell trucks to the Pakistan Army, Jeeps, second-hand armoured cars and helicopters.' He smiled. 'Have I disappointed you?'

She shook her head. 'The other side of war.' She hesitated. 'Do you miss it? The dark side, I mean?'

'Let's say there's nothing quite like it. There's no drug that could possibly match the force, the energy, of the killing time in which you're immersing yourself. War itself is the ultimate drug.'

She looked a bit shocked. 'Well… business must be booming, with the war spilling over from Afghanistan. Can I get you a drink?'

'Large vodka would be good, with iced tonic water and a twist of lemon.'

She was back in three minutes and handed it to him. 'Enjoy.'

He drank half of the drink straightaway and sat there, suddenly yawning. Since Lahore yesterday morning, he'd only had four hours' sleep. He finished the drink, put the glass down, tilted his seat back. A hell of a trip, and Afghanistan had been particularly rough, but bloody marvellous. The buzz of action never failed to thrill him. It was what he'd missed when he left the army.

You could make millions out of the sale of second-hand military equipment in Northern Pakistan-but there was a lot more money to be made from dealing in illegal arms. Even respectable firms were at it, and nobody was more respectable than Talbot International. Its Chairman, General Sir Hedley Chase, presented the face of integrity itself at the small but elegant office in Curzon Street. The real business took place in Islamabad, where dozens of firms jostled one another for advantage.