By dawn the next day he was completely lost on an open sea. During the night the freighter’s list had increased. Below decks the leaking chemicals had etched their way through the hull plates, and a phosphorescent steam enveloped the bridge. The engine room was a knee-deep vat of acid brine, a poisonous vapour rising through the ventilators and coating every rail and deck-plate with a lurid slime.

Then, as Johnson searched desperately for enough timber to build a raft, he saw the old World War II garbage island seven miles from the Puerto Rican coast. The lagoon inlet was unguarded by the US Navy or Greenpeace speedboats. He steered the Prospero across the calm surface and let the freighter settle into the shallows. The inrush of water smothered the cargo in the hold. Able to breathe again, Johnson rolled into Captain Galloway’s bunk, made a space for himself among the empty bottles and slept his first dreamless sleep.

‘Hey, you! Are you all right?’ A woman’s hand pounded on the roof of the staff car. ‘What are you doing in there?’

Johnson woke with a start, lifting his head from the steering wheel. While he slept the lianas had enveloped the car, climbing up the roof and windshield pillars. Vivid green tendrils looped themselves around his left hand, tying his wrist to the rim of the wheel.

Wiping his face, he saw the American biologist peering at him through the leaves, as if he were the inmate of some bizarre zoo whose cages were the bodies of abandoned motor-cars. He tried to free himself, and pushed against the driver’s door.

‘Sit back! I’ll cut you loose.’

She slashed at the vines with her clasp knife, revealing her fierce and determined wrist. When Johnson stepped onto the ground she held his shoulders, looking him up and down with a thorough eye. She was no more than thirty, three years older than himself, but to Johnson she seemed as self-possessed and remote as the Nassau school-teachers. Yet her mouth was more relaxed than those pursed lips of his childhood, as if she were genuinely concerned for Johnson.

‘You’re all right,’ she informed him. ‘But I wouldn’t go for too many rides in that car.’

She strolled away from Johnson, her hands pressing the burnished copper trunks of the palms, feeling the urgent pulse of awakening life. Around her shoulders was slung a canvas bag holding a clipboard, sample jars, a camera and reels of film.

‘My name’s Christine Chambers,’ she called out to Johnson. ‘I’m carrying out a botanical project on this island. Have you come from the stranded ship?’

‘I’m the captain,’ Johnson told her without deceit. He reached into the car and retrieved his peaked cap from the eager embrace of the vines, dusted it off and placed it on his head at what he hoped was a rakish angle. ‘She’s not a wreck — I beached her here for repairs.’

‘Really? For repairs?’ Christine Chambers watched him archly, finding him at least as intriguing as the giant scarlet-capped fungi. ‘So you’re the captain. But where’s the crew?’

‘They abandoned ship.’ Johnson was glad that he could speak so honestly. He liked this attractive biologist and the way she took a close interest in the island. ‘There were certain problems with the cargo.’

‘I bet there were. You were lucky to get here in one piece.’ She took out a notebook and jotted down some observation on Johnson, glancing at his pupils and lips. ‘Captain, would you like a sandwich? I’ve brought a picnic lunch — you look as if you could use a square meal.’

‘Well…’ Pleased by her use of his title, Johnson followed her to the beach, where the inflatable sat on the sand. Clearly she had been delayed by the weight of stores: a bell tent, plastic coolers, cartons of canned food, and a small office cabinet. Johnson had survived on a diet of salt beef, cola and oatmeal biscuits he cooked on the galley stove.

For all the equipment, she was in no hurry to unload the stores, as if unsure of sharing the island with Johnson, or perhaps pondering a different approach to her project, one that involved the participation of the human population of the island.

Trying to reassure her, as they divided the sandwiches, he described the last voyage of the Prospero, and the disaster of the leaking chemicals. She nodded while he spoke, as if she already knew something of the story.

‘It sounds to me like a great feat of seamanship,’ she complimented him. ‘The crew who abandoned ship — as it happens, they reported that she went down near Barbados. One of them, Galloway I think he was called, claimed they’d spent a month in an open boat.’

‘Galloway?’ Johnson assumed the pursed lips of the Nassau schoolmarms. ‘One of my less reliable men. So no one is looking for the ship?’

‘No. Absolutely no one.’

‘And they think she’s gone down?’

‘Right to the bottom. Everyone in Barbados is relieved there’s no pollution. Those tourist beaches, you know.’

‘They’re important. And no one in Puerto Rico thinks she’s here?’

‘No one except me. This island is my research project,’ she explained. ‘I teach biology at San Juan University, but I really want to work at Harvard. I can tell you, lectureships are hard to come by. Something very interesting is happening here, with a little luck..

‘It is interesting,’ Johnson agreed. There was a conspiratorial note to Dr Christine’s voice that made him uneasy. ‘A lot of old army equipment is buried here — I’m thinking of building a house on the beach.’

‘A good idea… even if it takes you four or five months. I’ll help you out with any food you need. But be careful.’ Dr Christine pointed to the weal on his arm, a temporary reaction against some invading toxin in the vine sap. ‘There’s something else that’s interesting about this island, isn’t there?’

‘Well…’ Johnson stared at the acid stains etching through the Prospero’s hull and spreading across the lagoon. He had tried not to think of his responsibility for these dangerous and unstable chemicals. ‘There are a few other things going on here.’

‘A few other things?’ Dr Christine lowered her voice. ‘Look, Johnson, you’re sitting in the middle of an amazing biological experiment. No one would allow it to happen anywhere in the world — if they knew, the US Navy would move in this afternoon.’

‘Would they take away the ship?’

‘They’d take it away and sink it in the nearest ocean trench, then scorch the island with flame-throwers.’

‘And what about me?’

‘I wouldn’t like to say. It might depend on how advanced…’She held his shoulder reassuringly, aware that her vehemence had shocked him. ‘But there’s no reason why they should find out. Not for a while, and by then it won’t matter. I’m not exaggerating when I say that you’ve probably created a new kind of life.’

As they unloaded the stores Johnson reflected on her words. He had guessed that the chemicals leaking from the Prospero had set off the accelerated growth, and that the toxic reagents might equally be affecting himself. In Galloway’s cabin mirror he inspected the hairs on his chin and any suspicious moles. The weeks at sea, inhaling the acrid fumes, had left him with raw lungs and throat, and an erratic appetite, but he had felt better since coming ashore.

He watched Christine step into a pair of thigh-length rubber boots and move into the shallow water, ladle in hand, looking at the plant and animal life of the lagoon. She filled several specimen jars with the phosphorescent water, and locked them into the cabinet inside the tent.

‘Johnson — you couldn’t let me see the cargo manifest?’

‘Captain… Galloway took it with him. He didn’t list the real cargo.’

‘I bet he didn’t.’ Christine pointed to the vermilion-shelled crabs that scuttled through the vivid filaments of kelp, floating like threads of blue electric cable. ‘Have you noticed? There are no dead fish or crabs — and you’d expect to see hundreds. That was the first thing I spotted. And it isn’t just the crabs — you look pretty healthy…’