We hire a car and driver at the airport, follow the course of the Indus through the mud-brick villages that line the valley: Choglamsar, whose inhabitants are refugees displaced by the invasion of Tibet; Shey; Thiksey; Ranbirpura.

Hemis Monastery stands in a dark adjunct running south of the main valley. Winter is stubbornly entrenched. Despite the bright sun, snow and ice cling to the road that winds up to it. You may need to shovel sand from the verge and spread it to help your tyres grip, while your ears sing at the altitude. Without the chance to acclimatise, your lungs and body will protest at the thinness of the air. The feeling of weakness in your oxygen-starved body is like a bitter foretaste of old age.

The low lintels of the monastery doorways will threaten to brain you. Sitting by a wood-burning stove in an upper room much like the one that Notovitch described, the present abbot will acknowledge that he has encountered the rumours before. You’re not the first to put the question: a Russian visitor, yes, a manuscript, yes, Jesus.

The story has altered over the years. In some you’ll hear Issa himself studied at Hemis. That’s not, as you know, the tale that Notovitch told.

Cross-legged on a soft mat, you take a dried apricot from the bowl in front of you, eat a cashew, thank him for the tea, ask to see the library.

The books, you’re pleased to see, are treated with veneration: their loose-leafed pages folded in cloths, pressed between boards and each one stored in a separate glassed-in niche. These are the Buddha’s teachings; these the commentaries. That’s what you’re told, anyway. Unless you read Tibetan, you’ll have to take their word for it.

‘Among all your books, could there be such a manuscript as Notovitch described, in Pali?’ How badly you want to believe!

The monk shakes his head. A secret book? ‘I don’t know,’ he says. It seems like the most unlikely answer of all. But you feel he is too honest to claim the book exists; too attuned to the motives of tourists to scotch the story once and for all.

There is one person he says you could ask for a definitive answer. The current Statsang Rinpoche. You jot down the address: Lhasa, People’s Republic of China. In an act whose cosmic wisdom is impenetrable to you, the present Rinpoche chose to be incarnated in Tibet, an occupied country, and is stuck there for the foreseeable future.

*