Andy McNab - Avenger

He waited for her to pass from left to right before beginning the follow. As Deveraux crossed the busy road and headed for the town centre, Danny was thirty metres behind her. It was the correct distance: any more than thirty metres and he could easily lose her in the crowd; any closer and she might just as easily realize that she was being followed.

Deveraux kept to the right-hand side of the road, so Danny crossed to the left. It was the best position, allowing a little more distance and giving a better view.

It had started well and Danny remembered to keep his eyes down on Deveraux's feet and the blue Nike trainers she was wearing rather than on the back of her head. That way, if she were to turn back suddenly, they were less likely to make accidental eye contact, which would blow the operation.

Danny knew that he had to remain third party aware too. And in these training exercises the third party included his grandfather, who seemed to have a knack for being in the right place when things went wrong for Danny.

Fergus knew the route Deveraux was taking and Danny was only too aware that his grandfather was being driven to different vantage spots so that he could watch his progress.

Deveraux was walking more slowly. Danny did the same – and checked out what was ahead of him so that if she stopped completely, he would have a reason for doing the same. He was in luck: there was a row of shops immediately ahead. Or was it just luck? His grandfather and Deveraux had devised this operation; they would want to see how he reacted to every change in the situation.

As Deveraux came to a halt at a bus shelter, joining two other people, Danny turned and checked out the kettles and radios in the window of a small electrical goods shop. He had his back to the target now, and she was unsighted, so he quickly moved back a little so that the area around the bus shelter was reflected in the window.

The target had been unsighted to him for two or three seconds, long enough to move away. Cars and trucks were passing, and the window Danny was looking into was smeared and grimy. His view was far from perfect but he could just make out the three figures inside the bus shelter. He reckoned that Deveraux's eyes would be burning into his back, just waiting for him to make the error of turning round to check that she was still there.

But Danny knew better than that, and he also knew that he couldn't stand staring at kettles indefinitely. He reached into a pocket of his bomber jacket and took out his mobile phone. It was switched off, but Danny acted as though he was answering a call as he continued to watch Deveraux's reflection in the grimy window.

She must have been satisfied with what he was doing because after another minute she was foxtrot again. After a few seconds, pretending to end the call, Danny was also on the move.

Soon after, Deveraux made another attempt at tricking him. He watched her take a right turn, and instead of following immediately, he walked past the junction and saw that she was still on the right-hand side of the road, passing a row of houses. He turned back and followed, still on the opposite side to Deveraux. She took another right, and Danny immediately became suspicious. Two right turns meant that Deveraux was heading back in the direction she had come from.

As Danny reached the next junction, he saw Deveraux take a third right. He knew exactly what she was doing. She was looping her track, checking to see whether she was being followed. For all Danny knew, she would be round the next corner, with Fergus sitting in a car nearby waiting for him to fall into the trap.

'You don't fool me, Marcie,' whispered Danny as he walked slowly back to the main road. He slipped into a phone box and went through the motions of pretending to make a call while he kept his eyes on the junction where his target was due to appear.

The phone box was good cover from both the third party and the target. When Deveraux appeared – if she appeared – she would see only a shadowy shape there.

Danny waited and began to grow anxious when Deveraux failed to arrive at the junction. Maybe he'd got it wrong; maybe the whole route was anti-surveillance. But his grandfather had told him many times that surveillance was not an exact science. No one could cover all the options. It was a question of weighing up those options and then making a decision. Danny was starting to think he had made the wrong decision, but then Deveraux finally appeared at the junction. He'd got it right.

She crossed the road and headed for the city centre: Danny said a 'See you then, mate' into the phone, replaced the receiver and started to follow.

In the main shopping area Deveraux lingered to look in a few windows and then Danny saw her check her watch. She started off again, making for a short-term car park. Suddenly she stopped and began speaking to a man heading in the same direction.

Danny went into a bookshop, picked up the first book he saw and, through the shop window, watched the two of them chatting across the street. The man was young; maybe a student. He was wearing trainers, jeans and a blue, chunky pullover.

They spoke for less than a minute and the young man pointed back towards a road in the precinct. Then, as he moved towards an alleyway into the car park, Deveraux took off her jacket.

That was it – the GO sign. As far as the exercise was concerned, Deveraux had been talking to Black Star.

Danny left the shop and headed towards the alleyway, walking swiftly but not running and drawing unwanted attention to himself.

He reached the alleyway and could see the car park at the end. He moved into the gloom of the building, his eyes scanning the immediate area for a glimpse of the blue pullover. He knew that the man was totally unaware that he had become involved in the operation; Deveraux had deliberately selected some unknown third party to give Danny the practice of following a real target.

The young man had disappeared and Danny looked for EXIT signs. He could only see one; about forty metres away to his half left. He made another decision. There was no time to search for Black Star – he might already be driving out of the car park; he might just be walking straight through. But options had to be weighed and decisions made.

Danny walked along to the exit and arrived just in time to see the young man in the blue pullover driving out of the car park in what remained of a rusting green X-reg Mini Metro. As the vehicle stopped at the main road, Danny kept walking, burning the car's registration number into his memory.

The Metro pulled away and disappeared into the traffic. That was it, the serial was over – there was no way Danny could follow Black Star on foot. He powered up his mobile and called Deveraux. She answered after a single ring.

'I've got a vehicle registration and a description for you.'

'End ex. We'll debrief back at the hotel. Now turn round.'

With the mobile still held to his ear, Danny followed the instruction. Deveraux was standing about twenty metres away next to the dark blue Vectra.

Fergus was sitting in the car's front passenger seat.

As Danny powered down his phone, he saw his grandfather's nod of satisfaction. Danny smiled; he'd done it.

The information that Black Star had promised arrived in the form of two e-mails, which revealed that Elena would be leaving the UK just three days later. Three days – hardly any time to make preparations, despite all the planning and hurried training that had already taken place.

New York was the destination: Deveraux's hunch had been correct. But there wasn't the time, or even the inclination, to score points in being proved right. There was too much to be done.

The first e-mail was an e-ticket, a return, economy-class flight from Heathrow to JFK, New York. Black Star had thought of everything; a one-way flight would have aroused the suspicions of US immigration officials. But they all knew that the bomb master had no intention of Elena being on board when the return aircraft left the ground.