‘But I like knitting, darling. I love it. And I think home-knitted garments are much nicer than bought ones.’

‘Must make your fingers ache, I should think,’ said Rupert. ‘Talk about wearing one’s fingers to the bone. I know the meaning of that phrase all right now, eh?’

‘Don’t be so silly,’ snapped Alice. ‘Of course it doesn’t make my fingers ache. I enjoy it. And I think it’s a great pity you’ve started smoking again.’

Rupert smoked five cigarettes that day and ten the next and the day after that Pamela and Guy came to stay for a fortnight’s holiday.

Rupert thought, and Alice agreed with him, that if you lived by the sea it was positively your duty to invite close friends for their summer holidays. Besides, Guy and Pamela, who hadn’t a large income, had two children at expensive boarding schools and probably would otherwise have had no holiday at all. They arrived, while their children were away camping, for the middle two weeks of August.

Pamela had not knitted a row since her daughter was two but she liked to watch Alice at work. She said she found it soothing. And when she looked inside the knitting drawer in the chest and saw the leftover hanks of yarn in such delectable shades, pinks and lilacs and subtle greens and honey yellows and chocolate browns, she said it made her feel she must take it up again, for clothes cost so much and it would be a great saving.

Guy was not one of those writers who never speak of their work. He was always entertaining on the subject of the intricate and complex detective stories he yearly produced and would weave plots out of all kinds of common household incidents or create them from things he observed while they were out for a drive. Alice enjoyed hearing him evolve new murder methods and he played up to her with more and more ingenious and bizarre devices.

‘Now take warfarin,’ he would say. ‘They use it to kill rats. It inhibits the clotting of the blood, so that when the rats fight among themselves and receive even a small wound they bleed to death.’

‘They give it to human beings too,’ said Alice, the nurse. ‘Or something very close to it. It stops clots forming in people who’ve had a thrombosis.’

‘Do they now? That’s very interesting. If I were going to use that method in a book I’d have the murderer give his victim warfarin plus a strong sedative. Then a small cut, say to the wrist . . .’

Another time he was much intrigued by a book of Alice’s on plants inadvisable for use in winemaking. Most illuminating for the thriller writer, he said.

‘It says here that the skunk cabbage, whatever that may be, contains irritant crystals of calcium oxalate. If you eat the stuff the inside of your mouth swells up and you die because you can’t breathe. Now your average pathologist might notice the swellings but I’d be willing to bet you anything he’d never suppose them the result of eating lysichiton symplocarpus. There’s another undetectable murder method for you.’