‘Spring tide,’ Richard said knowledgeably. ‘We’ll be able to find crabs in the rock pools near the house.’

‘What’s a spring tide?’ Conor asked.

‘We did them in geography,’ Richard said. ‘Like, four times a year the tide goes out really, really far?’

‘Oh yeah,’ Conor said.

The village itself was tiny: as they drove through it on the way to the house Conor saw a cluster of decrepit cottages ascending a steep street above a small fishing pier. At the top of this mild incline stood a country church with a pointed spire. A soft grey light filled the space between the seafront houses and the rock of the dismal harbour. Triangles of bunting – the remains of some summer festival – still clung damply to the peeling walls. In a fenced-off field a Friesian heifer browsed, flattered by its entourage of flies.

On the lawn of the big white house Katherine Culhane was waiting. Conor got out of the car and followed Richard across the wiry, seashell-pitted grass. The whole place smelled like some nautical catastrophe – like the rusted wreck of a brine-eaten trawler. Conor stepped over the scabbed, thorny crescent of a crab’s broken shell and shook hands with Katherine Culhane, who held a glass of wine, although it was only – Conor thought, with a sense of how gleefully his mother would disapprove – four in the afternoon.

They had dinner in the conservatory, with its view of the darkening sea. Once inside the house Conor was cosily reminded of home: here he found the same recessed lights and costly furniture that seemed to have been issued to every Dublin house he had ever visited.

After dinner Richard said he was tired and wanted to go to bed early. Conor, suddenly lost and homesick, said he would do the same. Peter said he thought this was a good idea.

Conor brushed his teeth in water that tasted salty, and he had an unpleasant, nonsensical image of Peter Culhane laying pipes on the beach, siphoning off seawater to save money on the family’s utility bills. In the near-darkness he lay in the unfamiliar bedroom listening for familiar sounds. But there was only the rasping sound of Peter Culhane, coughing and snuffling in the room next door.

Richard had only pretended that he was tired. While Conor lay awake in the room beneath him, Richard sat on his bed in the attic room playing a computer game and thinking.

Although he enjoyed the role of host – on that first afternoon he gave Conor a rapid tour of the island’s secret spots – Richard mildly resented Conor’s visit. He had developed the conviction that their friendship was a schoolbound affair, and that to drag it so peremptorily into the sacred space of the summer holidays was to subject it to pressures it had never been designed to withstand. He was also conscious, for the first time, of the fact that Conor’s family didn’t own a second house to which they could retreat every summer. He noticed that Conor was unfamiliar with things like spring tides and sailboats. In fact, Richard had begun to see himself as Conor’s economic and intellectual superior, and he was aware that his own capacity for pity wouldn’t be enough to see him through the two weeks they were supposed to spend together.