‘You exaggerate the power of upheaval which a worm would be able to bring into play in the limited time available,’ said Clovis; ‘if you put in a strenuous ten minutes with a really useful fork, the result ought to suggest the operations of an unusually masterful mole or a badger in a hurry.’

‘They might guess I had done it,’ said Mrs Thackenbury.

‘Of course they would,’ said Clovis; ‘that would be half the satisfaction of the thing, just as you like people at Christmas to know what presents or cards you’ve sent them. The thing would be much easier to manage, of course, when you were on outwardly friendly terms with the object of your dislike. That greedy little Agnes Blaik, for instance, who thinks of nothing but her food, it would be quite simple to ask her to a picnic in some wild woodland spot and lose her just before lunch was served; when you found her again every morsel of food could have been eaten up.’

‘It would require no ordinary human strategy to lose Agnes Blaik when luncheon was imminent: in fact, I don’t believe it could be done.’

‘Then have all the other guests, people whom you dislike, and lose the luncheon. It could have been sent by accident in the wrong direction.’

‘It would be a ghastly picnic,’ said Mrs Thackenbury.

‘For them, but not for you,’ said Clovis; ‘you would have had an early and comforting lunch before you started, and you could improve the occasion by mentioning in detail the items of the missing banquet—the lobster Newburg and the egg mayonnaise, and the curry that was to have been heated in a chafing- dish. Agnes Blaik would be delirious long before you got to the list of wines, and in the long interval of waiting, before they had quite abandoned hope of the lunch turning up, you could induce them to play silly games, such as that idiotic one of “the Lord Mayor’s dinner-party,” in which every one has to choose the name of a dish and do something futile when it is called out. In this case they would probably burst into tears when their dish is mentioned. It would be a heavenly picnic.’

Mrs Thackenbury was silent for a moment; she was probably making a mental list of the people she would like to invite to the Duke Humphrey picnic. Presently she asked: ‘And that odious young man, Waldo Plubley, who is always coddling himself—have you thought of anything that one could do to him?’ Evidently she was beginning to see the possibilities of Nemesis Day.

‘If there was anything like a general observance of the festival,’ said Clovis, ‘Waldo would be in such demand that you would have to bespeak him weeks beforehand, and even then, if there were an east wind blowing or a cloud or two in the sky he might be too careful of his precious self to come out. It would be rather jolly if you could lure him into a hammock in the orchard, just near the spot where there is a wasps’ nest every summer. A comfortable hammock on a warm afternoon would appeal to his indolent tastes, and then, when he was getting drowsy, a lighted fusee thrown into the nest would bring the wasps out in an indignant mass, and they would soon find a “home away from home” on Waldo’s fat body. It takes some doing to get out of a hammock in a hurry.’

‘They might sting him to death,’ protested Mrs Thackenbury.

‘Waldo is one of those people who would be enormously improved by death,’ said Clovis; ‘but if you didn’t want to go as far as that, you could have some wet straw ready to hand, and set it alight under the hammock at the same time that the fusee was thrown into the nest; the smoke would keep all but the most militant of the wasps just outside the stinging line, and as long as Waldo remained within its protection he would escape serious damage, and could be eventually restored to his mother, kippered all over and swollen in places, but still perfectly recognizable.’

‘His mother would be my enemy for life,’ said Mrs Thackenbury.