These gay costumes were a pretty sight against the background of trees and bushes and flower-beds. The sun had set, leaving a yellow glow in the sky, and the Chinese lanterns were beginning to glow in the gathering twilight. It was certainly a varied crowd; all centuries had met together. A Japanese damsel walked arm-in-arm with a Lancashire witch; an Italian peasant hob-a-nobbed with "The Queen of Sheba," a Spanish lady was talking to "Old Mother Hubbard," while such characters as "A Medicine Bottle," or "An Aeroplane" rubbed shoulders with an "Egyptian Princess" or "Dick Whittington's Cat." Miss Burd, garbed appropriately as Chaucer's Prioress, received the company at the top of the sun-dial steps, looking, in the opinion of the Foursome League, quite sufficiently like the ghost of yesterday to have justified squeals had they met her alone. When the ceremony of introduction was over, the guests dispersed about the lawn, Miss Perry struck up a waltz on the piano, and the fun began. Dancing on the grass, in the growing darkness, with the Chinese lanterns sending out a soft but uncertain radiance overhead, was a new experience to most of the school. It was difficult not to step on to the flower-beds, or to brush against the bushes. Trailing garments were decidedly in the way, and came to grief. There was a delirious sort of Eastern feeling about it--a kind of combination of "The Thousand and One Nights" and the "Rubaiyat of Omar Khayyam." The Abbey tower for once seemed out of place, and ought to have changed miraculously into a pagoda or a minaret. It was after the girls had been dancing for some little time that Ingred first noticed a couple whom she did not remember to have seen before. They followed persistently in her steps, and even gently bumped into her once or twice, thus compelling her attention. She looked at them, considerably mystified. One was attired in Early Victorian Costume, with a crinoline, a little tippet, and a poke bonnet, from which peeped some bewitching ringlets; the other, in a gorgeous Turkish costume, was enveloped in a shimmering gauze veil. "Who are those?" Ingred asked her partner. But Verity could not tell. In the twilight it was, of course, easy to make mistakes, but Ingred began to have a strong suspicion that neither of the mysterious partners belonged to the school. They were certainly not members of the Fifth or Sixth. Perhaps some of the Juniors had forced themselves in? No, they were too tall for Juniors. "Perhaps they are ghosts!" shivered Verity. "Ghosts don't bump into people. These are real substantial flesh and blood!" "It's so dark, we can hardly see." "Well, I vote we keep close to them, and next time we get near a lantern, we'll turn the tables and bump into them, and try to see who they are."