There was no need of the proverbial feather. Mrs. Muldoon made a grab at the settle but missed it. She caught at a chair, but that gave way. It was the floor that finally stopped her. "We're so sorry," apologised Victor. "We thought you knew. We ought to have said Mademoiselle Malvina." Mrs. Muldoon regained her feet, and without answering walked straight into the study. "They want to know," said Mrs. Muldoon, "if the Fairy's in." The Professor, with his back to the window, was reading. The light in the room was somewhat faint. "Who wants to know?" demanded the Professor. "The twins from the Manor House," explained Mrs. Muldoon. "But what?--but who?" began the Professor. "Shall I say 'not at home'?" suggested Mrs. Muldoon. "Or hadn't you better see them yourself." "Show them in," directed the Professor. They came in, looking a little scared and still holding one another by the hand. They wished the Professor good evening, and when he rose they backed away from him. The Professor shook hands with them, but they did not let go, so that Victoria gave him her right hand and Victor his left, and then at the Professor's invitation they sat themselves down on the extreme edge of the sofa. "I hope we do not disturb you," said Victor. "We wanted to see Mademoiselle Malvina." "Why do you want to see Mademoiselle Malvina?" inquired the Professor. "It is something very private," said Victor. "We wanted to ask her a great favour," said Victoria. "I'm sorry," said the Professor, "but she isn't in. At least, I don't think so." (The Professor never was quite sure. "She slips in and out making no more noise than a wind-driven rose leaf," was Mrs. Muldoon's explanation.) "Hadn't you better tell me? Leave me to put it to her." They looked at one another. It would never do to offend the wise and learned Christopher. Besides, a magician, it is to be assumed, has more ways than one of learning what people are thinking. "It is about mamma," explained Victoria. "We wondered if Malvina would mind changing her." The Professor had been reading up Malvina. It flashed across him that this had always been her speciality: Changing people. How had the Arlington twins discovered it? And why did they want their mother changed? And what did they want her changed into? It was shocking when you come to think of it! The Professor became suddenly so stern, that if the twins could have seen his expression--which, owing to the fading light, they couldn't--they would have been too frightened to answer. "Why do you want your mother changed?" demanded the Professor. Even as it was his voice alarmed them. "It's for her own good," faltered Victoria. "Of course we don't mean into anything," explained Victor. "Only her inside," added Victoria. "We thought that Malvina might be able to improve her," completed Victor.