Satisfied that Kolya was not a loathed Jew, Ivan took it upon himself to begin the boy’s nautical education. He showed him with great patience how to take a reading from a battered sextant, how to forecast weather from the clouds, and how to give a death blow with a knife. Once, he stood in the bow and persuaded a wild seabird to take bread from his hand; he talked matter-of-factly of killing a man. He liked to get drunk and sing loud, impassioned songs out of one side of his mouth, while his eyes rolled back into his head. He was vain, a bully, as fanatically loyal to the Tsar as one would expect; though not the least character in this story, he is far from the greatest. He was a sworn enemy of the Jewish people. The old man has no grounds to be fond or sentimental about his memory. Why does he dwell on him? Maybe it’s because a steppe-warrior making a home on the sea is as great a break with family tradition as Kolya’s.

It seems to the old man that so much that is deemed to be great or profound is merely tawdry when inspected, particularly the abstractions for which people are prepared to kill or die. Nowadays, he believes in nothing at all. The universe is a dark space which men fill with their own meanings. The mystery of a human being like Ivan only deepens on reflection. Each is an infinite paradox. But perhaps he presumes too much on the listener’s patience with his sermonising.

‘When we reached Varna, MacGahan took me on as her valet.’

From the deck of the Derby, which is riding at anchor, awaiting a visit from the port authority, Varna seems to sing an eternal song of seafaring and trade. The Black Sea port has been part of the Ottoman Empire for four centuries. Doubtless, there are harlots and spices, strong drink, and men with tattoos: the eternal ingredients of every maritime spell.

Yet sometimes, I feel this is not an enchantment at all, but a jury-rigged assembly of mirrors and lenses that enables us to peer back into the past. Valet. Swordstick. Combination drawers. The archaisms of our great-grandparents can lull us into a sense that their world was remote from ours. It’s not.

To Captain Meakins’s annoyance, there is not yet a telegraph station at Varna. But elsewhere, submarine cables are knitting the world into a web of synchrony. Time is becoming the same everywhere. The long and varied beats of the medieval year have given way to shorter cycles. It’s a meaningless cliché to say that the world is changing, but stories that have done for centuries are losing their place to newer ones. In Baku, oil wells have been sunk where the Zoroastrians once worshipped the fire god, Ahura Mazda. Steam trains rumble past temples honouring the Siva lingam on the Deccan Plateau. Even Japan, in occultation for more than two hundred years, is opening itself to the world. Everywhere printing presses and electric wires accelerate the passage of news and propaganda, multiply the intercourse of opposing fictions.