Mr. Maverick Narkom, Superintendent of Scotland Yard, looked up from the letter he was perusing, a wrinkle in his brow and one hand spread out over the sheet to keep it open, as the sound of a soft knock broke through the stillness, and with an exasperation born of the knotty problem upon which he was at work, called out an irritable "Come in."Inspector Petrie's head appeared in the aperture, stiff hand at the salute."I know you wasn't to be disturbed, sir," he began apologetically, "but there's a leddy come to see you. Seemed distressed, and said it was urgent, and begged me for the love of 'even to let her in."