They had walked beyond the weir to the stretch of river where the college eights practised. The clouds had dispersed and there was a band of clear sky, page white, above the trees. A light wind was swaying the branches. The Thames murmured, horses, cows, ducks. On sunny mornings, Dyer would run here. Had anyone the right to annihilate this? From somewhere, he heard the metallic notes of a marsh tit.

Marvar heard it too. In his coat, he stood and stared at the bare trees, searching for the source of the sound. He seemed infinitely sadder, now that he had unburdened himself. He had talked to Dyer as if he wanted to prolong the world for as long as possible without this knowledge. (‘How long would it take otherwise?’ ‘Years!’) He had no words left to say. Birds wheeled overhead, disappearing. The wind blew ripples on the water. He was one of the barges on the canal, rudderless, pot-plants in the little curtained windows, beer cans, the refuge for vagrants. He was back where he started when he stood blinking at Dyer outside the Oxford University Press, not knowing what to do.

Dyer pointed.

‘Look. He’s over there.’

Marvar followed the direction of Dyer’s finger to a dark tiny speck, balanced on the middle of three telephone wires like a solitary musical note.

‘He? How can you be so certain?’

It was Dyer’s turn to tell Marvar something he didn’t know: it had been an amateur who discovered that male cuckoos do the singing, as was the case for all songbirds.

Marvar shook his head; he had no idea. ‘You mean,’ in a slow, fascinated tone, ‘that if you hear a bird singing, it’s a male … Now that is incredible.’

For perhaps ten seconds more they stood in silence and listened, until the bird flew off.

Marvar gave a little sigh. He gently rubbed the back of his knuckles. ‘The atomic bombs – they had male names too, you know.’

Just then, as if a door had opened, a cold gust sprang up. Dyer looked at his watch. The football match would be over. Their two sons would be tucking into their prawn sandwiches and banana cake, supplied by a caterer in Summertown.

‘Why not come home for a drink – unless you’ve got other plans?’

‘Plans?’ It was an empty laugh, but a laugh nonetheless. ‘I have no plans.’

As they turned to go, the geese came over low up the river, a wedge of large brown Vs, sharp against the darkening sky, babbling, surging on.

Chapter Fifteen

FOR THE SECOND TIME THAT afternoon, Dyer relieved Marvar of his coat.

‘I could do with an overcoat like this. Where did you get it?’

They were standing in the hallway, next to the fishing rod.

‘Shula had it made for me before I came here,’ said Marvar.