Mop said in a breathy hysterical voice, ‘Suppose she goes about in the night to every place where they’ve got one? She goes about and watches over them and makes it happen. She’s down there now doing it. Listen!’

Glass against glass . . .

‘That’s crazy,’ I said. ‘It’s those books you read.’

She didn’t say anything. We closed the door and lay in our beds with the bedlamp on. The light made it better. We heard the clock strike twelve. I said ‘Can we go to sleep now?’ And when Mop nodded I put out the light.

The moon had gone away, covered perhaps by clouds. Into the black silence came a curious drawn-out cry. I know now what it was, but no child of eleven could know. I was only aware then that it was no cry of grief or pain or terror, but of triumph, of something at last attained; yet it was at the same time unhuman, utterly outside the bounds of human restraint.

Mop began to scream.

I had the light on and was jumping up and down on my bed, shouting to her to stop, when the door was flung open and Mrs Felton came in, her hair a wild heathery mass, a dressing gown of quilted silk, black-blood colour, wrapped round her and tied at the waist with savagery. Rage and violence were what I expected. But Mrs Felton said nothing. She did what I had never seen her do, had never supposed anything would make her do. She caught Mop in an embrace and hugged her, rocking her back and forth. They were both crying, swaying on the bed and crying. I heard footsteps on the garden path, soft, stealthy, finally fading away.

Mop said nothing at all about it to me the next day. She withdrew into her books and sulks. I believe now that the isolated demonstration of affection she had received from her mother in the night led her to hope more might follow. But Mrs Felton had become weirdly reserved, as if in some sort of long dream. I noticed with giggly embarrassment that she hardly seemed to see Mop hanging about her, looking into her face, trying to get her attention. When Mop gave up at last and took refuge in the garden with Dr James on demons, Mrs Felton lay on the dining room sofa, smoking and staring at the ceiling. I went in once to fetch my cardigan – for Mrs Potter was taking me to the medieval town at Lavenham for the afternoon – and she was still lying there, smiling strangely to herself, her long brown hands playing with her necklace of reddish-brown beads.

She went off for a walk by herself on Friday afternoon and she was gone for hours. It was very hot, too hot to be in a garden with only thin apple tree shade. I was sitting at the dining room table, working on a scrapbook of country house pictures Mrs Potter had got me to make, and Mop was reading, when the phone rang. Mop answered it, but from the room where I was, across the passage, I could hear Mr Felton’s hearty bray.