The Expensive Halo by Josephine Tey — Read

It was the beginning of November, and Ursula was giving a party. Lady Wilmington had gone to the country to assist in the organisation of a charity ball where everyone was going to be some kind of fish, and her husband had gone to earth in a remote part of the house with a bottle of port and the _Encyclopaedia Britannica_, which, with the _Daily Telegraph_ and the _Pig Breeder_, was his usual literary fare. The party was a more elaborate affair than Ursula's usual entertainments, which had, even the most forethought of them, an air of informality, a charade-like spontaneity. This was what Ursula called a Coggins party; that is, one at which all the servants from Coggins downwards assisted, and the guests had the run of the house instead of being confined to Ursula's flat. There was a definite programme of "turns," and there would be dancing afterwards in the ball-room. Ursula "received" her guests instead of greeting their arrival with a gesture from the middle distance.

"Darling," said Daphne, who had been in Cannes for a fortnight with a married sister, "you do it beautifully. I feel I ought to have a train. You might have borrowed some of your mother's armour, though. That breastplate thing with the ruby lion on it would have been frightfully impressive. Oh, _darling!_" clutching Ursula's arm as a memory struck her, "I almost forgot. Is it true?"