Cayo Esqueleto. Skeleton Key.

There it was, stretching out before him, thirty-eight kilometres long and nine kilometres across at its widest point. The sea around it, which had been an extraordinary, brilliant blue until a few minutes ago, had suddenly darkened, as if someone had thrown a switch. Over to the west, he could make out the twinkling lights of Puerto Madre, the island’s second biggest town. The main airport was further north, outside the capital of Santiago. But that wasn’t where he was heading. He pressed on the joystick and the plane veered to the right, circling over the forests and mangrove swamps that surrounded the old, abandoned airport at the bottom end of the island.

The Cessna had been equipped with a thermal intensifier, similar to the sort used in American spy satellites. He flicked a switch and glanced at the display. A few birds appeared as tiny pinpricks of red. There were more dots pulsating in the swamp. Crocodiles or perhaps manatees. And a single dot about twenty metres from the runway. He turned to speak to the man called Carlo but there was no need. Carlo was already leaning over his shoulder, staring at the screen.

Carlo nodded. There was only one man waiting for them, as agreed. Anyone hiding within a few hundred metres of the airstrip would have shown up. It was safe to land.

The pilot looked out of the window and there was the runway. It was a rough strip of land on the edge of the coast, hacked out of the jungle and running parallel with the sea. The pilot would have missed it altogether in the dying light but for the two lines of electric bulbs burning at ground level, outlining the path for the plane.

The Cessna swooped out of the sky. At the last minute it was buffeted about by a sudden, damp squall that had been sent to try the pilot’s nerve.