"I've changed my mind. No, I'm _not_ going to tell you. It's no use bothering me, for I just shan't." "I think everybody's horrid to-night," said Sadie, turning away much offended. It was on the very next evening that Ida Beckford, going to her bedroom in the gloaming, caught a glimpse of a white-robed figure with a cowl over its head gliding along the passage and up the stairs. Ida was not so strong-minded as Geraldine. She turned the colour of pale putty, and went straight downstairs again to relate her psychic experience to her fellow seniors. She did not meet with the sympathy she expected. "Some silly trick of those intermediates," sniffed Hilary. "I'll be down on them if they go shamming spooks," threatened Geraldine. "If it happens again we'll set a watch and catch it," declared Stuart loftily. Ida cheered up at this mundane view of the matter, and recovered her colour; but she abandoned the blotter she was going to fetch, and stayed in her form-room instead of walking upstairs again. The news began to creep about the school, however, that the Abbey was being haunted by a spiritual visitor. Many of the girls saw it glide along the landing in the dusk, and disappear up a certain narrow flight of stairs. Now herein lay the mystery. The stairs went up ten steps in full view of the passage, then they turned a sharp corner, rounded a yard of landing, and with four more steps ended in a locked attic door. Several of the most venturesome members of the school had tried to follow the figure, but when they came round the corner, to their immense surprise it had utterly disappeared. And there was absolutely no place in which it could possibly have concealed itself. "Has it crept through the keyhole?" quavered Peggy. "Or just vanished into thin air?" speculated Magsie. "The door's really locked!" declared Vi, rattling the handle again to make sure. "We certainly _saw_ it go up, but it's not here now!" "Flesh and blood can't disappear in a second!" "It's most uncanny!" "The old Cistercians wore white habits." "I say, I don't like this!" Brother Lawrence, as the girls began to call the apparition, showed himself frequently, but always with the same elusiveness. The phenomenon was invariably as before: his white monastic robes would glimmer through the darkness, glide up the stairway, and then seemingly melt into nothing. Geraldine herself pursuing hotly on the scent, found that she was utterly baffled. A head girl, especially a prefect with a scorn for superstition, does not like to admit herself baffled. Geraldine thought the matter over, took Loveday into her confidence, and went to Miss Todd. As the result of her interview she resolved to set what she called "a very neat little spook-trap". She and Loveday said nothing about it to the rest of the school. They merely bided their time.