Outstanding at mathematics as at English, Rougetel might have pursued a prodigious career as an academic or as a communications whizz-kid, or made his mark in government. But at the end of his first year at Cambridge, less than a month after he encountered Dyer on the towpath outside the Molesey Boat Club, he went on his long vac to Bolivia and failed to return. In his parents’ empty bedroom in La Paz, he lay with his eyes wide open in the dark and realised he had made his decision. That autumn, living off the proceeds from the sale of their house in Achumani, and off the rind of an insurance policy, he set out on the road that he had been treading ever since.

‘How to describe it? You could say it began as a Western interpretation of Eastern religions – the world is in yourself and also a reflection of what is in you.’ But quite a lot of it, Rougetel had come to realise, speaking now to Dyer, was a continuation of what they had been taught at the Phoenix.

Rougetel sucked his fingers clean. He was still hungry. Dyer ordered two rice cakes. Despite all the questions that he itched to ask, he said nothing else, he wanted Rougetel to continue, as once he had longed for Rejas to go on speaking, and more recently, Marvar. To interrupt at this point would be fatal.

The cakes arrived on a tray as Rougetel filled in the years:

The start of the Michaelmas term found him in the Arctic Archipelago. ‘I wanted to go as far as possible from everything I knew.’ Yielding to a similar impulse, he had run away from the Phoenix in his first term, disappearing on himself like an anorexic girl.

If you wish to look hard at your life, Father Lemoine had said, you must vacate it. Through a contact of Lemoine’s in the Oblate Fathers, who had a mission on King William Island, Rougetel lived two winters in a rancid-smelling igloo with Netsilik seal-hunters. Here he was released from the complications of the world that he had grown up in. The horizonless topography spoke to him of the early simplicity of the universe. He was shorn of possessions, not even the cut snow that formed his home of ice was his own. His deprivations taught him the skills which allowed him to survive on any roadside thereafter. No night had a chill after the extreme temperatures of the glacial ocean. No taste was too revolting after he drank tepid seal blood out of a caribou skull. He would rarely again experience anything quite so extreme.