Stephen, always alert to signs which might help him to decipher Cass, pricked up his ears.

‘Shall we make our way down then?’ said Cass, ignoring her sister’s remark.

They were going to swim in the river for the first time since Stephen’s arrival. The four of them trooped down the snowdrop field, not saying much. As on the first day, they followed the narrow path along the bank, winding in and out of the dappled shade of the trees. Today there were clouds of midges dancing near the surface of the water. At their swimming place a knotted rope swung out from a high branch across the water. The river curved here, and the water deepened around it. A few feet further along there was a gap in the trees where the flat rocks at the water’s edge had been paled and warmed by the sun. They left their clothes here and their towels; except Georgie, who carried on a way along the path.

‘Where are you going?’ Helena called out to her.

‘I want to skinny dip – I’m going to get in down here.’

‘She’s got the curse,’ Helena whispered to Stephen.

‘Pardon me?’ said Stephen.

‘Her period.’

Stephen recalled that girls at school had sometimes given in a note to the teacher to get off swimming: it was rumoured that you couldn’t swim at that time of the month. He wondered if it was because there’d be blood in the water, or whether it was that the girls got cramps. The thought of Georgie menstruating in the river stirred an unfamiliar feeling in him.

It didn’t occur to him that Helena’s recounting of intimate details went two ways. After the third night Helena had spent in Stephen’s room, Georgie couldn’t wait any longer to be told what she called ‘the gory details’. Helena had had her morning bath and was getting dressed in Georgie’s room.

‘Well, are you going to leave me in suspense for ever … what’s he like?’

‘Not like you’d think. He’s pretty fantastic, actually,’ said Helena.

‘How come? Does he recite Shakespeare’s soliloquies while he’s fondling your tits?’

Helena threw her hairbrush in Georgie’s general direction. ‘No!’

‘What, then?’

‘He’s really good at it.’

‘No!’

‘Yes. And he’s got a big knob.’

‘Like how big?’

‘Big.’

‘Blimey. I wouldn’t have guessed that somehow.’

‘I know.’

They both pondered the mystery before them.

‘I mean, how does he compare to Danny Gillespie?’