He tapped other tall piles that were examples of the genre he was studying: Ganghadara's. 'Forty six Transmigrations', the Tibetan text 'Twelve Manifestations of Padmasambhava', the guru who established Buddhism in Tibet; also the 'Biography of the Gyatso Rimpoche, Lives One Through Nineteen', which brought the Dalai Lama up to the present; Bao had once met this man, and had not realized then that his full biography would take up so many volumes.

Zhu Isao also had in his apartment copies of Plutarch's 'Lives', and Liu Xiang's 'Biographies of Exemplary Women', from about the same time as the Plutarch; but he admitted that he was finding these texts not as interesting as the reincarnation chronicles, which in certain cases spent as much time on their subjects' time in the bardo and the other five lokas as they did on their time as humans. He also liked the 'Autobiography of the Wandering Jew', and the 'Testaments of the Trivicurn jati', and a beautiful volume, 'Two Hundred and Fifty-three Travellers', as well as a scurrilous looking collection, possibly pornographic, called 'Tantric Thief Across Five Centuries'. All of these Zhu described to his visitors with great enthusiasm. They seemed to him to hold some kind of key to the human story, assuming there could be any such thing: history as a simple accumulation of lives. 'After all, in the end all the great moments of history have taken place inside people's heads. The moments of change, or the clinamen as the Greeks called it.'

This moment, Zhu said, had become the organizing principle and perhaps the obsession of the Samarqandi anthologist Old Red Ink, who had collected the lives in his reincarnation compendium using something like the clinamen moment to choose his exemplars, as each entry in his collection contained a moment when the subjects, always reincarnated with names that began with the same letters, came to crossroads in their lives and made a swerve away from what they might have been expected to do.

'I like the naming device,' Bao remarked, leafing through one volume of this collection.

'Well, Old Red Ink explains in one marginalia that it is merely a mnemonic for the ease of the reader, and that of course in reality every soul comes back with every physical particular changed. No telltale rings, no birthmarks, no same names – he would not have you think his method was anything like the old folk tales, oh no.'

The Minister for Natural Health asked about a stack of extremely slender volumes, and Zhu smiled happily. As a reaction against these endless compendiums, he explained, he had got into the habit of buying any books he came across that seemed required by their subject matter to be short, often so short that their titles would scarcely fit on their spines. Thus 'Secrets to Successful Marriage', or 'Good Reasons to Have Hope for the Future', or 'Stories About Not Being Afraid of Ghosts'.

'But I have not read them, I must admit. They exist only for their titles, which say it all. They could be blank inside.'

Later, outside on his balcony, Bao sat next to Zhu watching the city flow beneath them. They drank cup after cup of green tea, talking about many different things, and as the night grew late, and Zhu feeling pensive, it seemed, Bao said to him, 'Do you ever think of Kung Jianguo? Do you ever think of those times any more?'

'No, not very often,' Zhu admitted, looking at him directly. 'Do you?'

Bao shook his head. 'I don't know why. It's not as if it's so very painful to recall. But it seems so long ago.'

'Yes. Very long.'

'I see you still have a bit of a limp from that day.'

'Yes, I do. I don't like it. I walk slower and it's not so bad. But it is still there. I set off metal detectors in the high security zones.' He laughed. 'But it is a long time ago. So many lives ago I get them all confused, don't you?' And he smiled.

One of Zhu Isao's last sessions was a discussion of what purpose the study of history might have, and how it might help them now in their current predicament.

Zhu was tentative in this matter. 'It may be no help at all,' he said. 'Even if we gained a complete understanding of what happened in the past, it might not help us. We are still constrained in our actions in the present. In a way we can say that the past has mortgaged the future, or bought it, or tied it up, in laws and institutions and habits. But perhaps it helps to know as much as we can, just to suggest ways forward. You know, this matter of residual and emergent that we discussed – that each period in history is composed of residual elements of past cultures, and emergent elements that later on will come more fully into being this is a powerful lens. And only the study of history allows one to make this distinction, if it is possible at all. Thus we can look at the world we live in, and say, these things are residual laws from the age of the Four Great Inequalities, still binding us. They must go. On the other hand we can look at more unfamiliar elements of our time, like China's communal ownership of land, and say, perhaps these are emergent qualities that will be more prominent in the future; they look helpful; I will support these. Then again, there may be residual elements that have always helped us, and need to be retained. So it is not as simple a matter as "new is good, old is bad". Distinctions need to be made. But the more we understand, the finer we can make the distinctions.

'I begin to think that this matter of "late emergent properties" that the physicists talk about when they discuss complexity and cascading sensitivities, is an important concept for historians. justice may be a late emergent property. And maybe we can glimpse the beginnings of it emerging; or maybe it emerged long ago, among the primates and proto humans, and is only now gaining leverage in the world, aided by the material possibility of post scarcity. It is hard to say.'

He smiled again his little smile. 'Good words to end this session.'

His final meeting was called 'What Remains to be Explained', and consisted of questions that he was still mulling over after all his years of study and contemplation. He made comments on his list of questions, but not many, and Bao had to write as fast as he could to get the questions themselves recorded:

What Remains to be Explained Why has there been inequality in accumulation of goods since the earliest recorded history? What causes the ice ages to come and go? Could Japan have won its war of independence without the fortuitous combination of the Long War and the earthquake and fire striking Edo? Where did all the Roman gold end up? Why does power corrupt? Was there any way that the native peoples of the New World could have been saved from the devastation of Old World diseases? When did people first arrive in the New World? Why were the civilizations on Yingzhou and Inka at such different stages of development? Why can't gravity be reconciled mathematically with pulse microprobability? Would Travancore have initiated the modern period and dominated the Old World, if the Kerala had never lived? Is there life after death, or transmigration of souls? Did the polar expedition of the fifty second year of the Long War reach the south pole? What causes well fed and secure people to work for the subjugation and immiseration of starving insecure people? If al Alemand had conquered Skandistan, would the Sami people have survived? If the Shanghai Conference had not arranged such punitive reparations, would the postwar world have been more peaceful? How many people can the Earth support? Why is there evil? How did the Hodenosaunee invent their form of government? Which disease or combination of diseases killed the Christians of Firanja? Does technology drive history? Would things have turned out differently if the birth of science in Samarqand had not been delayed in its dispersal by the plague? Did the Phoenicians cross the Atlantic to the New World? Will any mammals larger than a fox survive the next century? Is the Sphinx thousands of years older than the Pyramids? Do gods exist? How can we return the animals to the earth? How can we make a decent existence? How can we give to our children and the generations following a world restored to health?