It was a quiet, grey afternoon. The distant hills were blotted out, but the rocky coast was as grand as ever, and the plash of the waves, as they broke on the beach beneath her, was sweeter in her ears than music. She was disturbed in her reverie by a step on the rocks, and for a moment her heart beat quicker. Then she almost laughed at her own stupidity. And well she might, for the step only heralded the approach of Matilda Cookson, with her smart hat and luxuriant red hair. "Where ever have you been, Miss Maclean?" she began rather breathlessly, seating herself on a ledge of rock. "I have been looking out for a chance of speaking to you for nearly a fortnight." Mona's face expressed the surprise she felt. "I have been away from home," she said. "What did you want with me?" "Away from home! Then you haven't told anybody yet?" Mona began to think that one or other of them must be the victim of delusional insanity. "Told anybody--_what?_" Matilda frowned. If Miss Maclean had really noticed nothing, it was a pity she had gone out of her way to broach the subject, but she could not withdraw from it now. "I thought you saw me--that day at St Rules." "_Oh!_" said Mona, as the recollection came slowly back to her. "So I did,--but why do you wish me not to tell any one?" Matilda blushed violently at the direct question, and proceeded to draw designs on the carpet of Castle Maclean with the end of her umbrella. She had intended to dispose of the matter in a few airy words; and she felt convinced still that she could have done so in her own house, or in Miss Simpson's shop, if she had chanced to see Miss Maclean alone in either place. But Mona looked so serenely and provokingly at home out here on the rocks, with the half-cut German book in her delicate white hands, that the whole affair began to assume a much more serious aspect. Mona studied the crimson face attentively. It had been her strong instinctive impulse to say, "My dear child, if you had not reminded me of it I should never have thought of the matter again," and so to dismiss the subject. But she was restrained from doing so by a vague recollection of her conversation with Dr Dudley about these girls. She forgot that she was supposed to be their social inferior, and remembered only that she was a woman, responsible in a greater or a less degree for every girl with whom she came in contact. She laid her hand on her visitor's shoulder. "You may be quite sure," she said, "that I don't want to get you into trouble, but I think you had better tell me why you wish me not to speak of this."