I

Knox was suffering a little from remorse when he banged on Rebecca’s door at five the next morning. That man in the restaurant last night had been a dick; she’d been entitled to her revenge, especially considering the extraordinary strain she was under. His job had been to back her up, not slap her down. But when he tried to make amends by offering to carry her bag down to the taxi, she shook her head and assured him coolly that she could handle it fine by herself, thanks.

The port was already buzzing when they arrived, though the sun wasn’t yet up. High on a crane, a welder showered sparks as if celebrating fiesta. Ropes creaked alarmingly as a container vessel unloaded a huge net swollen with wooden crates. Last night’s whores boiled up coffee and rice for their men; children huddled beneath blankets on the sea wall, and fished for crabs. Small waves rocked the Yvette softly against the tractor-tyre buffers of the port wall. Knox jumped down on to its deck, turned to help Rebecca, but she ignored him, pointedly making her own way down.

He checked over the boat once more. A moderate westerly was pinning them to the jetty. He started the motor and left it idling while he freed the fore and aft mooring ropes from their steel mushrooms, stowed them away. He pushed against the harbour wall, burbled them clear of the harbour and its traffic. Then he turned the engine off again, unfurled their mainsail, took his seat at the stern and adjusted the rigging until suddenly it swelled pregnant with the breeze and they were off, passing through thin banks of predawn mist.

The sky began to lighten over the rocky silhouette of land, revealing thatch shanty towns on the shore, the marooned and rotted carcasses of metal and wooden hulls. Herons, whimbrels and plovers waded the mudflats and shallows with their curious jerky, backward walks. A pair of fishermen pushed their pirogue out into the shallows, then jumped aboard and paddled vigorously out towards them. Knox looked at Rebecca, sitting on the starboard bench, staring out towards land. ‘So was it true, then?’ he asked.

She turned to him with a raised eyebrow, though he was sure she knew what he was talking about. ‘Was what true?’

‘That stuff last night. About sex tourists having dicks like betting-pencils, living with their mothers until they’re ninety-five.’

Her chin lifted defiantly. ‘It was true of him.’

He couldn’t help but laugh, and his laughter was so obviously unaffected that it seemed finally to thaw her. Their eyes met briefly but then she hurriedly looked away again, almost in confusion. ‘So you’re a freelance, eh?’ she asked. ‘Any particular specialty?’

Knox shrugged. He’d been expecting this, had decided to hew as close to the truth as possible. ‘Archaeology and history, mostly.’

‘Hence that salvage ship?’

‘Yes.’

‘The interview I read with that guy. He reckoned the Chinese made it to America before Columbus.’

‘Yes,’ agreed Knox. ‘That’s what he reckons.’

Rebecca laughed. ‘So weren’t the Chinese frightened of sailing off the edge of the world, then, like all the Europeans?’

Knox hesitated. ‘That’s a bit of a myth, actually,’ he said finally. ‘No one ever truly believed the earth was flat.’ He pointed away to the western horizon. ‘Think about it. Any sailor could tell you the world was round. All they had to do was climb their mast and look at the curvature of the sea. You didn’t even need a boat, just a high cliff. And if there was no sea to hand, there were plenty of other ways. You could watch the shadow cast by the earth during a lunar eclipse, or measure the different lengths of shadow similar objects left at different latitudes.’ He sat forward, his enthusiasm getting to him. ‘There was this extraordinary Alexandrian called Eratosthenes. He actually calculated the circumference of the earth that way back in around 300 BC, and he got it right to within a percentage point.’

‘Huh. So where did the flat-earth idea come from, then?’

Knox smiled. ‘It’s the fault of your people, as it happens.’

‘My people?’

‘Sure,’ he nodded. ‘Darwinists; evolutionists. Though, to be fair, it really started with an American essayist called Washington Irving. He wrote a romanticised account of Columbus’s voyages, I guess in around 1830, though don’t hold me to that. It praised Columbus for defying the conventional wisdom of his time, risking sailing over the edge of the world for the sake of expanding knowledge. But it was complete nonsense. You’ve got to remember that Columbus didn’t head off searching for a new world; he was just looking for a shortcut to the Spice Islands.The people who argued against him pointed out that such a voyage was too far to be practicable, because they correctly believed the earth to be about twenty-three or twenty-four thousand miles in circumference; but Columbus refused to accept their estimate, insisting that it was only seventeen thousand miles around, which meant that Japan was just two and a half thousand miles west of Spain.’

‘And how far is it really?’

‘Ten or eleven thousand miles. Something like that. But the point is, Washington Irving knew all this. Everyone did. He never meant for his version of the story to be seen as historically accurate. But somehow the idea caught on. People began to believe flat-earthers had been for real. And then Darwin came along with all his disturbing ideas about evolution, and a lot of people took fright and tried to rubbish him away. The science got lost; it became a propaganda war. And a couple of Darwin’s defenders, Draper and Dickson White, I think their names were—’

‘Yes,’ said Rebecca. ‘That sounds right.’

‘They decided attack was the better form of defence. They wanted to make the point that just because an idea is revolutionary doesn’t mean it’s wrong; and also to poke a little fun at people who insisted on clinging to stupid ways of thinking even in the teeth of irrefutable evidence.’

‘So they accused them of being flat-earthers?’ laughed Rebecca. ‘Nice.’

‘Exactly. Pure propaganda. And incredibly effective. Too effective. Now anytime someone criticises a new theory, they’re just another flat-earther. It’s pretty unfair, when you think about it. And unnecessary, too. They could have accused them of being like the people who attacked Copernicus and Galileo for putting the sun at the centre of the solar system. Or they could have even accused them of being bulge-earthers.’

Rebecca squinted at him. ‘Bulge-earthers?’

‘Oh, man,’ laughed Knox. ‘This is going to get complex. Maybe that’s why they didn’t use it, come to think of it. You’ve got to go back to the Greeks. Everything was made up of four elements: earth, fire, air and water.’ The Indians, Japanese and plenty of others had believed in there being just four or five elements, but it had been the Greeks who’d influenced the Europeans, and it had been the Europeans who’d believed in the bulging earth. ‘Earth was the heaviest element, of course, because it fell through air and water. It therefore had to lie at the centre of the universe. Second heaviest was water, which surrounded earth; then came air, which surrounded water, and fire, which flamed upwards in air. But Christianity had a problem with this view, because the universe was God’s creation, and therefore perfect; and it stood to reason that a perfect universe would be arranged in a series of perfect concentric circles, with earth at its centre, and the sun, the moon, the planets and the stars all revolving around it.’

‘Why would that be a problem?’

‘Because if you put your perfect circles together with your differently weighted elements, the earth should logically have been an absolutely round ball completely submerged by water.’

‘Ah. So we should all have drowned by now? Or be fish?’

‘This was a serious conundrum,’ said Knox. ‘Medieval scholars really fretted about this stuff.’

‘And what was their explanation?’

‘It’ll sound weird, but effectively they decided that God had wanted to create man, and therefore had needed dry land, so He’d arranged the universe’s mix of elements and gravitational fields in such a way that the earth bobbed in the great world ocean, rather like an apple in a bucket.’

‘So just the top bit is exposed?’

‘Exactly. But that creates problems of its own, not least that all of the world’s exposed land had to be gathered in one place. There simply couldn’t be any land on the other side of the world.’

‘And people really believed this?’

‘Oh, yes. It was pretty much accepted wisdom in Europe in Columbus’s time; so the argument against him wasn’t just that the voyage he proposed was many thousands of miles longer than he believed; but also that it would be across a wilderness of water, and that therefore they’d have no chance of finding land and restocking on the way. But Columbus knew that there was land to the west, because he’d seen Iceland for himself; he’d heard about Greenland, Newfoundland and maybe even the northern US from the men of Bristol, who regularly fished off those coasts. And that was why he dismissed the arguments of the Spanish courtiers, and had the courage to set off.’

‘Bulge-earthers,’ smiled Rebecca, glowing with the new knowledge. ‘I’m going to have to use that in my next series.’