‘And one to our guide, whose fingers must be turning blue with the cold water.’

A second cheer went up.

‘But, most of all, I think it incumbent upon me to make this speech in the name of my dear old papa. Peace to the nigga!’

At this, he raised his glass higher still, so that his arm was completely straight; his hand holding the brimming glass was directly over his head. When he mentioned his father, I felt a stiffening in the group, a quick gagging at the peculiar smell of a good joke gone bad. There was another cheer, but this one was ragged; it frayed into nervous laughter. The boat wobbled in the river as his weight swapped from one foot to the other, and the puntman, who was standing side on on the back board, had to shift on to his heels, then back to his toes.

‘Or rather, not to Papa, but to Rebecca Newman, his private secretary, who has loved me like her own son, and who has gone to the trouble of forging his signature on the birthday card she sent to me from his office, and an excellent effort it is too, though Papa puts a little more oomph into the loops of the ascenders. She should not have tried to put one over on someone who has received as many cheques from him as I have, though I appreciate the effort!’ He drained off his glass.

‘Francis,’ Jessica said, so quietly it was almost to herself.

‘But he is no doubt away on important business. Guarding our borders, saving us from ourselves, kicking out the riffraff . . .’ he was rambling.

‘Francis, old chap, I think you ought to sit down.’ Michael rose from his seat and clambered over the shifting deck towards Francis. What began as a steadying hand on his arm quickly became downward pressure.

‘Falstaff, unhand me! I have a horror of doing what I ought.’

‘Sit down, Francis.’

The two men wrestled for a few seconds, the puntman vainly remonstrating with them both, but unable to abandon his pole. A great whoop went up from the drunken party as the scuffle carried Francis’s calves to the wooden sides of the boat, and he dodged, throwing Michael into the cold and murky water. Francis turned to face him and burst into laughter.

‘That is the best present a man could hope for,’ he said to the spluttering figure that surfaced from the river. ‘You are a true friend.’

For a moment, clouds of outrage gathered in Michael’s cheeks; he looked like a spoilt child preparing a tantrum. The water, which was so shallow it only came up to his waist, had undone the careful arrangement of his hair, revealing his bald patch. However, he saw the laughing faces of his friends in the punt and instead of raging he smiled graciously, and gave Francis a playful knock on the shins. Then he gripped the side of the boat and wobbled it as if to tip us all in.