Dyer glimpsed Marvar in scraps of conversation. At High Table in Trinity, from a Fellow who was a brain surgeon, Dyer heard the story of a terribly sick man who had been delivered unconscious in a military ambulance to the John Radcliffe, and carried to his own room in the John Warin ward, where he was guarded by two armed soldiers who conveyed to doctors and nurses that they must not comment on or remember anything the man might say in his ravings. Not one of his friends or relatives was allowed to be with him during his last hours. The surgeon had seen the body. He started to describe someone bearing no resemblance to Marvar – short, slight, grey hair – and was surprised when Dyer laughed suddenly.

In a story of ‘rickety authority’ – i.e. Cubbage – Updark had heard that ‘oil men’ might be involved, and that operatives working for Exxon or Chevron had abducted Marvar. ‘The rumour is – and I underline rumour – he may be in Houston.’

Hissop, meanwhile, was following a lead that the weapons industry lay behind Marvar’s disappearance.

Dyer detested these scenarios. Against the vacuum of hard, verifiable fact, he elaborated another theory, one that his most superstitious and stubborn self held to be no more rickety: from his safe place of refuge near Howtown, Marvar had contacted General Damghani of the Revolutionary Guard, and they had hammered out a deal – as once upon a time Rejas had made a pact with Calderón in order to see Yolanda again.

In Dyer’s alternative fictional version, Marvar had said to himself something like this. The whole universe came into being by fusion, built up from a pea soup of hydrogen, with a cosmic explosion; its moment had arrived, no army in the world could stop it; whatever human beings were capable of, nuclear fusion was a factor we were all going to have to live with, for good or bad, and if that was the case then what did it matter who had it first, whether it was the Iranians or the Americans or the British, because everyone would have it in the end, and that included Israelis, Saudis, Chinese, North Koreans, even tribes on the Amazon; but personally Marvar could not, in the end, exist one further moment without Shula.

‘There’s always a woman.’

Dyer had a persistent vision of Marvar peering down at a narrow country lane, straining his eyes.

It was already afternoon, the wind was stirring the grass. Dyer could see them on the skyline, near the grazed peak. The wind was flogging Marvar’s hair into his eyes. He was still climbing.

Again, he turns. The view to the lake. The conifers outlined against Martindale church. But not a stir in the valley below.

Then he spots it, a white dot moving through the bracken.