‘She told me the story of her birth and parentage.’

Kolya, as Notovitch, in his mid-seventies, is still a magpie. Vincenzo sees it in small things at first – a word or inflection lifted from him and handed back as though it’s newly minted. One day, he arrives to find the old man wearing a carefully folded cravat in the open collar of his shirt – Vincenzo’s unvarying attire. Where others might be embarrassed to mention the cravat, Vincenzo is one generation up from peasant and exercises the licence it gives him to be blunt. ‘You’ve copied me,’ he says.

‘I often wear a cravat,’ the old man replies, with a disarming innocence. ‘You haven’t noticed?’

If Notovitch could appropriate such trivial plumage from a virtual nonentity, imagine his debt to MacGahan.

This story is Kolya’s. I’m trying to tell it economically, but completely. I’m confining myself to the events and characters that gave his life its particular shape, which led to the incident that defined him in the eyes of posterity. These aren’t formless imaginings – though perhaps it seems so at times. We are working towards a point where the conjectured happenings of a fictional past converge with the account of history. And I’m keen to avoid those breaks in energy that can affect a discontinuous narrative. The supreme ambition you can have for a book is for it to be one thing: a single utterance in which every word plays a part.

But MacGahan’s story is so pertinent to Kolya’s, the story of her life, her apostasy, her disavowed religion; they influenced him so strongly that we’re going to have to risk another digression.

Of all the stories of which our world is made, the tales of the creator and the redeemer, the tales of the spirit and the Holy Word, are the most powerful. I know in my bones that when Leonard went to war it was for many reasons, but not the least was for an idea of duty sanctified by religion.

Kolya belongs to the oldest monotheists of all, the Jews, the trunk of the Abrahamic tree; MacGahan to one of its youngest offshoots: the Mormon heresy.

Imagine, then, me and you, on a distant planet, scrutinising light and sound waves that have drifted through the dark emptiness of interstellar space. Imagine, sifting through the effusions of eternity, that we could home in on a single speaker at a single moment in time. Imagine we’ve found MacGahan reclining on the cushions of the Turkish seraglio, all washed and anointed by her handmaidens, and Kolya recalled from a long exile in the hallway to share a sobering coffee, seethed in a copper ibrik and tasting like thimblefuls of mud. Now imagine we could hear her speak.

‘Her family were Latter-Day Saints.’

‘You know what a Mormon is?’

Kolya shakes his head. Two of the girls play with each other’s bracelets. The third snoozes in MacGahan’s lap; the pallor of her sleeping face makes the rouge on her cheeks look garish.