Alex didn’t make a conscious decision to follow the guard, but over the next few days he seemed drawn to him almost as if by accident. He spotted him twice more; once searching handbags at gate five and again giving directions to a couple of spectators.

Unfortunately, it was impossible to keep track of him all the time. That was the one flaw in Crawley ’s plan. Alex’s job as a ballboy kept him on Centre Court throughout much of the day. The ballboys and girls worked a rotation system, two hours on, two hours off. At best, he could only be a part-time spy. And when he was actually on court, he quickly forgot the guard, the telephone and the entire business of the break-in as he found himself absorbed by the drama of the game.

But two days after Blitz had left Wimbledon, Alex found himself once again shadowing the guard. It was about half an hour before afternoon play was due to begin and Alex was about to report into the Complex when he saw him entering the Millennium Building again. That was strange in itself. The building had its own security staff. The public couldn’t get past the reception desk without a pass. So what was he doing inside? Alex glanced at his watch. If he was late, Walfor would yell at him and possibly even move him to one of the less interesting perimeter courts. But there was still time. And he had to admit, his curiosity was aroused.

He went into the Millennium Building. As usual, nobody questioned him. His ballboy uniform was enough. He climbed the stairs, passed through the players’ lounge and into the restaurant at the other side. The guard was there, ahead of him. Once again he had his mobile phone in his hand. But he wasn’t making a call. He was simply standing, watching the players and the journalists as they finished their lunch.

The dining room was large and modern, with a long buffet for hot food and a central area with salads, cold drinks and fruit. There must have been about a hundred people eating at the tables and Alex recognized one or two famous faces among them. He glanced at the guard. He was standing in a corner, trying not to be noticed. At the same time, his attention seemed to be fixed on a table next to one of the windows. Alex followed the direction of his gaze. There were two men sitting at the table. One was wearing a jacket and tie. The other was in a tracksuit. Alex didn’t know the first man but the second was Owen Bryant, another world-class player, an American. He would be playing later that afternoon.

The other man could have been his manager, or perhaps his agent. The two of them were talking, quietly, intensely. The manager spoke and Bryant laughed. Alex moved further into the restaurant, keeping close to the wall. He wanted to see what the guard was going to do, but he didn’t want to be seen. He was glad that the restaurant was fairly crowded. There were enough people moving about to screen him.

Bryant stood up. Alex saw the guard’s eyes narrow. Now the mobile phone was on its way to his ear. But he hadn’t dialled a number. Bryant went over to a water dispenser and pulled a cup out of the plastic cylinder. The guard pressed a button on his phone. Bryant helped himself to some water. Alex watched as a bubble of air mushroomed up to the surface inside the plastic tank. The tennis player carried the water back to the table and sat down. The manager said something. Bryant drank his water. And that was it.

Alex had seen the whole thing.

But what had he seen?

He had no time to answer the question. The guard was already moving, heading for the exit. Alex came to a decision. The main door was between himself and the guard and now he made for it too, keeping his head low as if he wasn’t looking where he was going. He timed it perfectly. Just as the guard reached the door, Alex crashed into him. At the same moment, he swung an arm carelessly, knocking the guard’s hand. The mobile phone fell to the floor.

“Oh-I’m sorry,” Alex said. Before the guard could stop him, he had leant down and picked up the phone. He weighed it in his hand for a moment before passing it back. “Here you are,” he said.

The guard said nothing. For a moment his eyes were locked into Alex’s and Alex found himself being inspected by two very black pupils that had no life at all. The man’s skin was pale and pockmarked, with a sheen of sweat across his upper lip. There was no expression anywhere on his face. Alex felt the telephone being wrenched out of his hand and then the guard had gone, the door swinging shut behind him.

Alex’s hand was still in mid-air. He looked down at his palm. He was worried that he had given himself away, but at least he had learned something from the exchange. The mobile phone was a fake. It was too light. There was nothing on the screen. And it had no recognizable logo: Nokia, Panasonic, Virgin… nothing.

He turned back to the two men at the table. Bryant had finished his water and crumpled the plastic cup in his hand. He was shaking hands with his friend, about to leave.

The water…

Alex had had an idea that was completely absurd and yet made some sort of sense out of what he had seen. He walked back across the restaurant and crouched down beside the dispenser. He had seen the same machines all over the tennis club. He took a cup and used its rim to press the tap underneath the tank. Water, filtered and chilled, ran into the cup. He could feel it, ice cold against his palm.

“What the hell do you think you’re doing?”

Alex looked up to see a red-faced man in a Wimbledon blazer towering over him. It was the first unfriendly face he’d seen since he had arrived. “I was just getting some water,” he explained.

“I can see that! That’s obvious. I mean, what are you doing in this restaurant? This is reserved for players, officials and press.”

“I know that,” Alex said. He forced himself not to lose his temper. He had no right to be here and if the official-whoever he was-complained, he might well lose his place as a ballboy. “I’m sorry, sir.” he said. “I brought a racquet over for Mr. Bryant. I delivered it just now. But I was thirsty, so I stopped to get a drink.”

The official softened. Alex’s story sounded perfectly reasonable. And he had enjoyed being addressed as “sir”. He nodded. “All right. But I don’t want to see you in here again.” He reached out a hand and took the plastic cup. “Now on your way.”

Alex arrived back at the Complex about ten minutes before play began. Walfor glowered at him but said nothing. That afternoon, Owen Bryant lost his match against Jacques Lefevre, the same unknown Frenchman who had so unexpectedly beaten Jamie Blitz two days before. The final score was 6-4, 6-7,4-6, 2-6. Although Bryant had won the first game, his play had steadily deteriorated throughout the afternoon. It was another surprising result. Like Blitz, Bryant had been a favourite to win.

Twenty minutes later, Alex was back in the basement restaurant, sitting with Sabina, who was drinking a Coke Lite.

“My mum and dad are here today,” she was saying. “I managed to get them tickets and in return they’ve promised to get me a new surfboard. Have you ever surfed, Alex?”

“What?” Alex was miles away.

“I was talking about Cornwall. Surfing…”

“Yes, I’ve surfed.” Alex had learned with his uncle, Ian Rider. The spy whose death had so abruptly changed Alex’s life. The two of them had spent a week together in San Diego, California. That had been years ago. Years that sometimes felt like centuries.

“Is there something wrong with your drink?” Sabina asked.

Alex realized he was holding his Coke in front of him, balancing it in his hand, staring at it. But he was thinking about water.

“No, it’s fine…” he began.

And then, out of the corner of his eye, he saw the guard. He had come back downstairs into the Complex. Once again he was using the telephone in the corner. Alex saw him put in a coin and dial a number.