Waugh had one extraordinary experience in his Brazilian travels. On the long trek back from disappointing Boa Vista, he set out alone before dawn one day, confidently riding towards the encampment of St Ignatius. The Catholic priest there, tactful Father Mather, was the kindest of hosts. He would be pleasantly surprised by Waugh's unexpected appearance at midday.

Waugh was under the impression that he knew his way. There was the familiar line of the hills; here the creek that the map erroneously marked as a substantial river. Here, too, was a clear path through the savannah's dry scrub. The early morning was fresh and cool; the horse stepped out briskly. The day wore on; the sun grew hot; the path dwindled and disappeared. Waugh dismounted to lead his exhausted horse. He had eaten nothing the night before. He had no provisions. His native guides were hours behind him. He was thirsty, hungry, and lost. ‘It was one of the low spots of the journey,’ he remarks, with studied understatement. ‘I had been given a medal of St Christopher before I left London. I felt that now, if ever, was the moment to invoke supernatural assistance. And it came’ (92 Days 110).

In quick succession Waugh found water – a broad creek flowing in the wrong direction. Horse and man drank and set out again. ‘And there the real miracle occurred.’ He came across a Wapishiana Indian outside his solitary hut saddling an ox. He spoke English. He was setting out for Bon Success via St Ignatius. His wife gave Waugh a copious meal. Waugh was too tired to do more than collapse in the old man's hammock, and calculate the likelihood of such a collocation of coincidences. He estimated a cumulative probability of 1:54,750,000 before he even reached the end of the sequence. Being no mathematician, he gave up and assigned the play of chance to a benevolent intervention by St Christopher.

At the end of Ninety-Two Days Waugh sums up his downbeat account as a ‘direct, and I hope accurate’ chronicle. ‘It makes no claims to being a spiritual odyssey. Whatever changes there were – and all experience makes some change – are the writer's own property and not a marketable commodity.’ His statement prompts, and forbids, further rumination by an outsider.