When his time is almost up, he spends a couple of months volunteering at an orphanage outside Madras in order to satisfy some vague notion of ‘giving something back’. He makes an attempt to teach the children English – more use to them than Russian – but they’re not interested and the heat is so overwhelming that he soon abandons the pretence of work. In the mornings, he eats a hearty breakfast with the nice Swedish missionaries who are putting him up and then goes for a walk along the beach. Sometimes he’ll swim, or watch the local fishermen landing their catch. Most afternoons he takes a nap, has a half-hearted Tamil lesson, and reads or plays carom until supper time. Still, in later years he’ll earn a surprising amount of kudos from people when he tells them about this humanitarian interlude.

In the centre of the city, beside the sea, he watches blocks of ice being loaded into the thick masonry of an icehouse. Parcelled up in straw and sacking, the ice blocks have been carried across the ocean from the lake in Maine where they are cut each winter. They lose half their weight in transit, but there’s enough of them left to be sold as a luxury in the tropical heat, to chill the sahibs’ gin and tonics and make iced puddings for their wives and children. Nicolas feels grudging admiration for this evidence of British ingenuity. It’s further proof that the world is shrinking. He’s moved to buy a postcard of the icehouse and send it to his brother with cheery greetings. ‘The Twentieth Century, here we come!’ he writes.

Towards the end of 1884, he makes his slow, touristic way north. He hasn’t slept with another woman since Bessie – opportunities are scarce and he’s fearful of contracting something from the native brothels, but in Goa he enjoys a minor romance with a German backpacker from Cologne. They agree, insincerely, to stay in touch. As he leaves, it crosses his mind how nice it would be to be going home to someone.

A month later, travelling north out of Uzbekistan through the frontier statelets of the new Russian Imperium, Nicolas sees a huge earthwork rising out of the desert floor. It is a ghost town: all that remains of the once-prosperous city of Otrar. Nicolas scrambles onto one of its embankments. The top is flat. Lizards scuttle through the rust-coloured dried grass. Under his feet, shards of bones and fragments of broken pots testify to a previous existence as a thriving desert oasis. ‘I’m king of the world!’ he shouts, to the amusement of his local guides. ‘Look upon my works, ye mighty, and despair!’

This barren space was once a city of a quarter of a million people. Most of the pot shards underfoot are simple pieces of terracotta, but one or two have the striking blue glaze of precious azurite, which Nicolas has seen being laboured out of the ground on a tour of the lapis lazuli mines in Badakhshan. The raw mineral gives little hint of the celestial blue with which it has clothed portraits of the Virgin Mary for more than five hundred years, but Nicolas still buys a chunk from the gift shop as a present for Father David.