…still circling him, as if choosing its moment…

…and it might not have seen him. No. That wasn’t possible. A shark’s eyes are ten times more sensitive than a human being’s. Even in pitch darkness it can see eight metres away. And anyway, it doesn’t need eyes. It has receptors built into its snout which can detect even the tiniest electrical current. A beating heart, for example.

Alex tried to force himself to calm down. His own heart was generating minute amounts of electricity. His terror would guide the creature towards him. He had to relax!

What else? Don’t splash. Don’t make any sudden movements. Advice given to him by Ian Rider came echoing back across the years. A shark will be attracted to shiny metal objects, to brightly coloured clothes, and to fresh blood. Alex slowly turned his head. His oxygen cylinder had been painted black. His T-shirt was white. There was no blood. Was there?

He turned his hands over, examining himself. And then he saw it. Just above the wrist on his left arm. There was a small gash. He hadn’t even noticed it, but now he remembered catching his wrist on the side of the boat as he fell backwards. A tiny amount of blood, brown rather than red, twisted upwards out of the wound.

Tiny, but enough. A shark can smell one drop of blood in twenty-five gallons of water. Who had taught him that? He had forgotten, but he knew it was true. The shark had smelled him…

…and was still smelling him, slowly closing in…

The circles were getting smaller. The shark’s fins were down. Its back was arched. And it was moving in a strange, jerky pattern. The three textbook signs of an imminent attack. Alex knew that he had only seconds between life and death. Slowly, trying not to make any disturbance in the water, he reached down. The knife was still there, strapped to his leg, and he carefully unfastened it. The weapon would be tiny against the bulk of the great white and the blade would seem pathetic compared to those vicious teeth. But Alex felt better having it in his hand. It was something.

He looked around him. Apart from the cave itself, there was nowhere to hide-and the cave was useless. The mouth was too wide. If he went inside, the shark would simply follow him. And yet, if he made it to the ladder, he might be able to climb it. That would take him out of the water-up the Devil’s Chimney and onto dry land. True, he would surface in the middle of the Casa de Oro.

But no matter how bad General Sarov might be, he couldn’t be worse than the shark.

He had made his decision. Slowly, keeping the shark in his sight, he began to move towards the cave’s entrance. For a moment he thought the shark had lost interest in him. It seemed to be swimming away. But then he saw that he had been tricked. The creature turned and, as if fired from a gun, rushed through the water, heading straight for him. Alex dived down, air exploding from his lungs. There was a boulder to one side of the cave and he tried to wedge himself into a corner, putting it between himself and his attacker. It worked. The shark curved away. At that moment, Alex lunged forward with the knife. He felt his arm shudder as the blade cut into the thick hide just under the two front fins. As the shark flickered past, he saw that it was leaving a trail of what looked like brown smoke. Blood. But he knew that he had barely wounded it. He had managed a pinprick, nothing more. And he had probably angered it, making it all the more determined.

Worse, he was bleeding more himself. In his attempt to get out of the way, he had backed into the coral, which had cut his arms and legs. Alex felt no pain. That would come later. But now he really had done it. He had advertised himself: dinner, fresh and bleeding. It was a miracle that the great white hadn’t been joined by a dozen friends.

He had to get into the cave. The shark was some distance away, out to sea. The cave entrance was just a few metres away to his left. Two or three kicks and he would be in-then through the stalactites and stalagmites and onto the ladder. Could he do it in time?

Alex kicked with all his strength. At the same time he was thrashing with his hands and cursed noiselessly as he accidentally dropped the knife. Well, it would do him no good anyway. He kicked a second time. The entrance to the cave loomed up in front of him. He was in front of it now but not inside…

…And he was too late! The shark came hurtling towards him. The eyes seemed to have grown bigger. The mouth was stretched open in a snarl that contained all the hatred in the world. Its mouth was gaping, the dreadful teeth slicing through the water. Alex jerked backwards, twisting his spine. The shark missed him by centimetres. He felt the surge of water pushing him away. Now the shark was in the cave, but he wasn’t. It was turning to attack again, and this time it wouldn’t be confused by the rock wall and the boulders. This time Alex was right in its sights.

And then it happened. Alex heard a metallic buzz and, in front of his eyes, the stalagmites rose out of the floor and the stalactites dropped out of the ceiling, teeth that skewered the shark not once, but five or six times. Blood exploded into the water. Alex saw the dreadful eyes as its head whipped from side to side. He could almost imagine the creature howling in pain. It was completely trapped, as if in the jaws of a monster even more dreadful than itself. How had it happened? Alex hung in the water, shocked and uncomprehending. Slowly the blood cleared. And he understood.

Turner and Troy had been wrong a second time. Sarov had known about the Devil’s Chimney and he had made sure that nobody could reach it by swimming through the cave. The stalagmites and stalactites were fake. They were made of metal, not stone, and were mounted on some sort of hydraulic spring. Swimming into the cave, the shark must have activated an infra-red beam which in turn had triggered the ambush. Even as he watched, the deadly spears retracted, sliding back into the floor and ceiling. There was a hum and the body of the shark was sucked into the cave, disappearing into a trap. So the place even had its own disposal system! Alex was beginning to understand the nature of the man who lived in the Casa de Oro. Whatever else he might be, Sarov left nothing to chance.

And now he knew what had happened to the two CIA agents. Alex felt sick. All he wanted to do was get away. Not just out of the water but out of the country. He wished he had never come.

There was still a lot of blood in the water. Alex swam quickly, afraid that it would attract more sharks. But he paced himself, carefully measuring his ascent towards the surface. If a diver rises too quickly, nitrogen gets trapped in the bloodstream causing the painful and potentially lethal sickness known as the bends. That was the last thing Alex needed right now. He spent five minutes at three metres’ depth-a final safety stop-then came up for air. The whole world had changed while he had been underwater. The sun had rolled behind the horizon and the sky, the sea, the land, the very air itself had become suffused with the deepest crimson. He could see Garcia’s boat, a dark shadow, about twenty metres away and swam over to it. Suddenly he was cold. His teeth were chattering-although they had probably been chattering from the moment he had seen the shark.

Alex reached the side of the boat. Garcia was still sitting on the deck with a cigarette between his lips but didn’t offer to help him out.

“Thanks a bunch,” Alex muttered.

He slipped off his BCD-the oxygen tank came with it-and heaved it onto the boat, then pulled himself out of the water. He winced. Out of the water, he could feel the wounds that the coral had inflicted on his limbs. But there was no time to do anything about that now. As soon as he was standing on the deck, he unhooked his weight belt and dumped it to one side along with his mask and snorkel. There was a towel in Turner’s bag. He took it out and used it to rub himself dry. Then he went over to Garcia.