An hour later, Alex was still there. He was dirty and crumpled and he had a raging thirst. He looked to one side where a couple of old, splintered doors led into men’s and women’s toilets. There might be a tap inside but would the water even be drinkable? A guard in a brown shirt and trousers stood watching, leaning against the wall beside a floor-to-ceiling mirror, a machine-gun cradled in his arms. Alex wanted to stretch his arms but he was too hemmed in. There was an old woman with grey hair and a sagging face standing right next to him. She smelled of cheap perfume. As he half-turned, he found himself almost embraced by her and recoiled, unable to hide his disgust. He glanced up and saw that there was a single security camera set in the ceiling. He remembered how worried Joe Byrne had been about security at Santiago Airport. But it seemed to him that just about anyone could have walked in and nobody would have noticed. The guard looked bored and half asleep. The camera was probably out of focus.

At last they reached passport control. The official behind the glass screen was young, with black greasy hair and glasses. Turner slid three passports and three completed immigration forms through. The official opened them.

“Don’t fidget, Alex,” Troy said. “We’ll be through in a minute.”

“Sure, Mom.”

The passport man looked up at them. His eyes showed no welcome at all. “Mr Gardiner? What is the purpose of your visit?” he demanded.

“Vacation,” Turner replied.

The man’s eyes flickered briefly over the passports and then at the people to whom they belonged. He slid them under a scanner, yawning at the same time. The guard that Alex had noticed was nowhere near. He was gazing out of the window, watching the planes.

“Where do you live?” the official asked.

“ Los Angeles.” Turner’s face was blank. “I’m in the movie business.”

“And your wife?”

“I don’t work,” Troy said.

The official had come to Alex’s passport. He opened it and checked the picture against the boy who stood in front of him. “Alex Gardiner,” he said.

“How you doing?” Alex smiled at him.

“This is your first trip to Cayo Esqueleto?”

“Yeah. But I hope it won’t be my last.”

The passport official stared at him, his eyes magnified by the glasses. He seemed completely uninterested. “What hotel are you staying at?” he asked.

“The Valencia,” Turner said quietly. He had already written the name on the three immigration forms.

Another pause. Then the official picked up a stamp and brought it crashing down three times-three gunshots in the confined space of the kiosk. He handed back the passports. “Enjoy your visit to Cayo Esqueleto.”

Alex and the two CIA agents passed through the immigration room and into the luggage hall where their cases were already waiting, circling endlessly on an old, creaking conveyor belt. And that was it, Alex thought. It couldn’t have been easier! All that fuss and he hadn’t even been needed in the first place.

He picked up his case.

At the same time, although he was unaware of it, his picture and passport details were already being transmitted to police headquarters in Havana, Cuba, along with those of Turner and Troy. The “family” had actually been photographed three times. Once by the overhead camera that Alex had seen in the arrivals lounge, but which was far more sophisticated than he would have believed. As old-fashioned as it looked, it could zoom in on the hole in a man’s button or a single word written in a diary and blow it up fifty times if needed. They had been photographed a second time by a camera behind the mirror next to the toilets. And finally, a profile close-up shot had been taken by a camera concealed in a brooch worn by an old lady who smelled of cheap perfume and who had not, in fact, arrived on a plane but who was always there, mingling with the new arrivals, moving in on anyone who had aroused the suspicions of the people she worked for. The immigration forms that Turner had filled in were also on their way, sealed in a plastic bag. His answers to the standard questions mattered less to the authorities than the forms themselves. The paper had been specially formulated to record fingerprints, and in less than an hour these would be digitally scanned and checked against a huge database in the same police building.

The invisible machine that operated in the airport at Santiago had been focused on Turner and Troy before they had even arrived. They were American. They had said they were on vacation and their luggage (which had, of course, been searched as it came off the plane) contained the sunscreen, beach towels and basic medicines that you would expect an ordinary American family to pack. The labels on their clothes showed that they had all been bought in Los Angeles. But a single receipt tucked into the top pocket of one of Turner’s shirts told another story. He had recently bought a book from a shop in Langley, Virginia. Langley is where the headquarters of the CIA are based. The little scrap of paper had been enough to set alarm bells ringing. This was the result.

The officer in charge of security at the airport was watching them carefully. He was sitting in a small, windowless office and their images were right in front of him, on a bank of television screens. He watched them as they continued out of baggage reclaim and into the arrivals hall. His finger hovered briefly beside a red button on his console. It still wasn’t too late. He could pull them back in before they had reached the taxi stand. There were plenty of cells buried deep in the basement. And when normal questioning failed, there were always drugs.

And yet…

The head of security was called Rodriguez and he was good at his job. He had interrogated so many American spies that he sometimes said he could recognize one at a hundred metres. He had spotted “Mr and Mrs Gardiner” before they had even crossed the runway and had sent out his deputy to take a closer look. This was the bored-looking guard that Alex had seen.

But this time Rodriguez wasn’t sure-and he couldn’t afford to make mistakes. After all, Cayo Esqueleto needed its tourists. It needed the money that tourism brought. He might have his suspicions about the two adults, but they were two adults travelling with a child. He had overheard the brief conversation between Alex and the passport official. There were microphones concealed throughout the immigration hall. How old was the boy? Fourteen? Fifteen? Just another American kid being given two weeks on the beach.

Rodriguez made up his mind. He lifted his hand away from the alarm button. It was better to avoid the bad publicity. He watched the family disappear into the crowd.

Even so, the authorities would keep an eye on them. Later that day, just to be on the safe side, he would compile a report which would be sent along with the photographs and fingerprints to the local police in Cayo Esqueleto. A copy would also be forwarded to the very important gentleman who lived in the Casa de Oro. And perhaps someone would be sent to the Hotel Valencia to keep a close eye on the new arrivals.

Rodriguez settled in his chair and lit a cigarette. Another plane had landed. He leaned forward and began to examine the arriving crowd.

The Valencia was one of those amazing hotels that Alex usually saw in dream holiday prizes on game shows. It was tucked away in a crescent-shaped cove with miniature villas spread out along the beach and a low-rise reception area almost lost in a miniature jungle of exotic shrubs and flowers. There was a doughnut-shaped swimming pool with a bar in the inner ring and stools poking up just above the level of the water. The whole place seemed to be asleep. This was certainly true of the few guests Alex could see, lying motionless on sun-loungers.