As I went downstairs feeling remarkably useless, I realized that she must have heard something or she wouldn’t be lying awake. It was too late now to do anything about it. Whatever damage there was had already been done to her.

After a while, as neither Monica nor Derek returned, I telephoned Syl to ask what was going on. He spoke softly but without whispering, so I gathered that Monica had not left the house but Syl had closed the sitting-room door before answering the phone.

‘She’s sunk half the decanter of brandy,’ he said.

‘Has she told you what happened?’ I asked.

Syl hesitated. ‘She’s told me some of it but I think there’s more. She keeps opening her mouth and staring at me in a maddish kind of way, then closing it again...’

I interrupted him. ‘Did she tell you she tried to murder Derek?’

‘Well, she didn’t quite put it like that...’ said Syl.

I interrupted him again. ‘Do you think she did?’ I asked, suddenly wondering if a corpse was lying somewhere in this silent house.

‘Oh come on, Mum,’ said Syl. ‘Monica’s just upset...’

‘How do you know?’ I demanded, thinking of Monica’s usual ladylike demeanour and the stories I had read of mild-mannered little men who the neighbours insisted wouldn’t have hurt a fly and under whose cellar floors were found grisly things.

‘I think what’s really annoying her,’ said Syl, now lowering his voice further, ‘is that Derek’s taken up with some teenaged typist.’

‘Did he tell her?’ I asked, reflecting that it was often this type of admission that led to murder.

‘I think it was his parting shot,’ said Syl. ‘They were arguing about something or other and then he mentioned this girl—hang on... Monica, I’m just talking to Mum...’

‘Hallo,’ said Monica’s voice still sounding high and strange as she took the phone. ‘Has he come back?’

‘No...’ I said, intending to tell her that Margaret was all right.

But she wasn’t listening. She said, ‘Can I stay here? I don’t want to see him.’

‘Well, of course...’ I said, but she’d hung up.

I sat all night wrapped in a rug I found in the cloakroom. I’d locked the doors and I must admit I took a cursory survey of the ground floor to ascertain that Derek’s lifeless body was not indeed littering up some corner. Then I stayed awake reading one of Monica’s novels in case Margaret should cry out. I thought it strange that Monica had not mentioned the child. She was usually an oppressively careful mother.