One evening, Dyer’s father had played a game in which he studied the faces at the bar and imagined if they’d been fish to what species they belonged. Up until this moment, the playing fields of North Oxford had served to camouflage Gilles. A gagged voice somewhere in Dyer had kept trying to tell him: Never trust a grown man who shows pictures of himself on a podium. Yet Pierre’s father for the most part had blended in successfully with the other touchline dads; he was merely one of a shoal of undifferentiated scavengers.

Now in this river valley, Gilles Asselin had swum into view: he had the sharpened head and coiled aggression of Esox lucius. His type was durable, with jaws developed in the Cretacean period. Like the northern pike, he had survived a score of Ice Ages, travelling up becks and streams, from Oxford to Moscow, across the Himalayas to Beijing, and over the oceans to New York and Montreal.

He was looking at Dyer with his pikey eyes. ‘You know, Jean, I wouldn’t go too near the Russians right now.’

Dyer said evenly: ‘Who would you go near – aside from Estonians, naturally?’

Gilles took a sip of shandy and, without commenting on it, put down his glass. ‘Being French-Canadian, the Americans maybe.’

‘What, like Bonnie Cubbage?’

‘Dear Bonnie.’

‘I’m not overly keen on evangelists.’

‘That rules out an Arab then.’

‘An Israeli, too, probably.’

‘Pity. They’re so attractive, straight-backed. All that military service. How about a Persian?’ and kicked his feet together, waiting for Dyer’s reply.

‘What, like Scheherazade?’

‘Peut-être. Peut-être.’ A merciless look had come into his eyes. ‘Or Shula Marvar.’

‘By the way,’ said Dyer undaunted, ‘it was her husband I was ringing you about. I may have been the last person to see him.’

‘Not quite.’

Dyer glanced at Gilles.

‘Silvi didn’t tell you? Someone else saw Marvar after you.’

‘Who was that?’

Gilles picked up a ceramic salt cellar from the table and toyed with it. ‘Moi.’

His morning jog on that Sunday had taken him past the Phoenix. He noticed Marvar sitting by the edge of the sandpit, holding a book. ‘He was wearing a suit, like he might have been going to the service in Hall.’ At the sight of Gilles, Marvar scrambled to his feet and gave a reluctant wave.

Gilles couldn’t say if this had any connection with Marvar’s unannounced arrival, three hours later, at the Asselins’ house. Gilles was not at home, he had stepped out to the Covered Market to buy cheese. Marvar, as Dyer was bound to know, had turned up – unexpectedly early – to collect Samir. ‘He seems to have been in a mighty haste to get to wherever he was going.’

‘What do you think has happened to him?’