The story was first published in the first Indian edition of Plain Tales from the Hills in 1888, and in subsequent editions of that collection. Plain Tales from the Hills is available from Amazon with these notes as an e-book, price £1.56, and in many paperback editions.
Two sisters, Edith and Maud who have "a strong likeness between them in look and voice" are both in love with Saumarez. At a moonlight picnic he plans to ask Edith to marry him, but in the dark and confusion of a dust-storm he proposes to Maud by mistake. With much embarrassment and unhappiness he corrects his error.
Some critical comments
Charles Carrington in Rudyard Kipling, His Life and Work [Macmillan 1955] p 95, comments that this is "a vulgar, improbable tale, revealed, as Oscar Wilde put it, by lurid flashes, but strangely moving. The desultory talk, the suburban morality, the salacious prying into this very private affair, form the monochrome background against which the lightning reveals the naked will of the lovers in reckless realism. When daylight comes the other jaded picknickers look as unreal as actors bowing before the curtain... This was the method that Kipling was to elaborate in his maturer works: he would construct a frame about his picture and contrast the picture with the frame.