She shivered in the bottom of the boat.

Suddenly angry, Kheim said loudly to the Miwok headman, 'We brought a disease with us, by accident!'

Ta Ma stared at him.

'Butterfly, please tell him something. Say something.'

She raised her head up and shouted something. Ta Ma took two steps out, going waist deep in the water. Kheim rowed out a couple of strokes, cursing. He was angry and there was no one to be angry at.

'We have to leave!' he shouted. 'We're leaving! Tell him that,' he said to Butterfly furiously. 'Tell him!'

She called out to Ta Ma, sounding distraught.

Kheim stood up in the boat, rocking it. He pointed at his neck and face, then at Ta Ma. He mimicked distress, vomiting, death. He pointed at the village and swept his hand as if erasing it from a slate. He pointed at Ta Ma and gestured that he should leave, that all of them should leave, should scatter. Not to other villages but into the hills. He pointed at himself, at the girl huddling in the boat. He mimed rowing out, sailing away. He pointed at the girl, indicating her happy, playing, growing up, his teeth clenched all the while.

Ta Ma appeared to understand not a single part of this charade. Looking befuddled, he said something.

'What did he say?'

'He said, what do we do?'

Kheim waved at the bills again, indicating dispersion. 'Go!' he said loudly. 'Tell him, go away! Scatter!'

She said something to her father, miserably.

Ta Ma said something.

'What did he say, Butterfly? Can you tell me?'

'He said, fare well.'

The men regarded each other. Butterfly looked back and forth between them, frightened.

'Scatter for two months!' Kheim said, realizing it was useless but speaking anyway. 'Leave the sick ones and scatter. After that you can regather, and the disease won't strike again. Go away. We'll take Butterfly and keep her safe. We'll keep her on a ship without anyone who has ever had smallpox. We'll take care of her. Go!'

He gave up. 'Tell him what I said,' he asked Butterfly. But she only whimpered and snivelled on the bottom of the boat. Kheim rowed them back to the ship and they sailed away, out the great mouth of the bay on the ebb tide, away to the south.

Butterfly cried often for the first three days after they sailed, then ate ravenously, and after that began to talk exclusively in Chinese. Kheim felt a stab every time he looked at her, wondering if they had done the right thing to take her. She would probably have died if they had left her, I Chen reminded him. But Kheim wasn't sure even that was justification enough. And the speed of her adjustment to her new life only made him more uneasy. Was this what they were, then, to begin with? So tough as this, so forgetful? Able to slip into whatever life was offered? It made him feel strange to see such a thing.

One of his officers came to him. 'Peng isn't on board any of the ships. We think he must have swum ashore and stayed with them.'

Butterfly too fell ill, and I Chen sequestered her in the bow of the flagship, in an airy nest under the bowsprit and over the figurehead, which was a gold statue of Tianfei. He spent many hours tending the girl through the six stages of the disease, from the high fever and floating pulse of the Greater Yang, through the Lesser Yang and Yang Brightness, with chills and fever coming alternately; then into Greater Yin. He took her pulse every watch, checked all her vital signs, lanced some of the blisters, dosed her from his bags of medicines, mostly an admixture called Gift of the Smallpox God, which contained ground rhinoceros horn, snow worms from Tibet, crushed jade and pearl; but also, when it seemed she was stuck in the Lesser Yin, and in danger of dying, tiny doses of arsenic. The progress of the disease did not seem to Kheim to be like the usual pox, but the sailors made the appropriate sacrifices to the smallpox god nevertheless, burning incense and paper money over a shrine that was copied on all eight of the ships.

Later, I Chen said that he thought being out on the open sea had proven the key to her recovery. Her body lolled in its bed on the groundswell, and her breathing and pulse fell into a rhythm with it, he noticed, four breaths and six beats per swell, in a fluttering pulse, over and over. This kind of confluence with the elements was extremely helpful. And the salt air filled her lungs with qi, and made her tongue less coated; he even fed her little spoonfuls of ocean water, as well as all she would take of fresh water, just recently removed from her home stream. And so she recovered and got well, only lightly scarred by pox on her back and neck.

They sailed south down the coast of the new island all this while, and every day they became more amazed that they were not reaching the southern end of it. One cape looked as if it would be the turning point, but past it they saw the land curved south again, behind some baked empty islands. Farther south they saw villages on the beaches, and they knew enough now to identify the bath temples. Kheim kept the fleet well offshore, but he did allow one canoe to approach, and he had Butterfly try speaking to them, but they didn't understand her, nor she them. Kheim made his dumb show signifying sickness and danger, and the locals paddled quickly away.

They began to sail against a current from the south, but it was mild, and the winds were constant from the west. The fishing here was excellent, the weather mild. Day followed day in a perfect circle of sameness. The land fell away cast again, then ran south, most of the way to the equator, past a big archipelago of low islands, with good anchorages and good water, and seabirds with blue feet.

They came at last to a steeply rising coastline, with great snowy volcanoes in the distance, like Fuji only twice as big, or more, punctuating the sky behind a steep coastal range, which was already tall. This final giganticism put paid to anyone's ability to think of this place as an island.

'Are you sure this isn't Africa?' Kheim said to I Chen.

I Chen was not sure. 'Maybe. Maybe the people we left up north are the only survivors of the Fulanchi, reduced to a primitive state. Maybe this is the west coast of the world, and we sailed past the opening to their middle sea in the night, or in a fog. But I don't think so.'

'Then where are we?'

I Chen showed Kheim where he thought they were on the long strips of their map; east of the final markings, out where the map was entirely blank. But first he pointed to the far western strip. 'See, Fulan and Africa look like this on their west sides. The Muslim cartographers are very consistent about it. And Hsing Ho calculated that the world is about seventy five thousand li around. If he's right, we only sailed half as far as we should have, or less, across the Dahai to Africa and Fulan.'

'Maybe he's wrong then. Maybe the world occupies more of the globe than he thought. Or maybe the globe is smaller.'

'But his method was good. I made the same measurements on our trip to the Moluccas, and did the geometry, and found he was right.'

'But look!' Gesturing at the mountainous land before them. 'If it isn't Africa, what is it?'

'An island, I suppose. A big island, far out in the Dahai, where no one has ever sailed. Another world, like the real one. An eastern one like the western one.'

'An island no one has ever sailed to before? That no one ever knew about?' Kheim couldn't believe it.

'Well?' I Chen said, stubborn in the face of the idea. 'Who else before us could have got here, and got back to tell about it?'

Kheim took the point. 'And we're not back, either.'

'No. And no guarantee we will be able to do it. Could be that Hsu Fu got here and tried to return, and failed. Maybe we'll find his descendants on this very shore.'

'Maybe.'

Closing on the immense land, they saw a city on the coast. It was nothing very big compared to back home, but substantial compared to the tiny villages to the north. It was mud coloured for the most part, but several gigantic buildings in the city and behind it were roofed by gleaming expanses of beaten gold. These were no Miwok!