What she was doing in Tom Beach’s genial house was plain enough. Her son had brought her to inspect Sally Winslow, as a man brings a vet to the horse he fancies. But it was not plain why Alexander Faulks fancied Sally Winslow. Imagine a bulldog after a butterfly. But bulldogs have a sense of humour. Sally Winslow is a wisp of a creature who has no respect for anyone, even herself. Under her bright bobbed hair, indeed, is the daintiest colour; but when some fellow said she had the face of a fairy, a woman suggested the face of a fairy’s maid. She listened to Alexander’s heavy talk and watched him in a fearful fascination, but sometimes she shot a glance across the table where a little man with a curly head and a roguish eye was eating his dinner demurely. His worst enemies never said that Captain Bunny Cosdon’s manners were bad. Now you know them all. When they made up a four for bridge, upon which Mrs. Faulks always insists, it was inevitable that Reggie Fortune should stand out, for his simple mind declines to grasp the principles of cards. Alexander Faulks in his masterful way directed Sally to the table; and scared, but submissive, she sat down and giggled nervously. Reggie found himself left to his hostess and Captain Cosdon. They seemed determined to entertain him and he sighed and listened. So he says. He is emphatic that he did not go to sleep. But the study of the events of that evening which afterwards became necessary, makes it clear that a long time passed before Alice Beach was saying the first thing that he remembers. “Did you ever know a perfect crime, Mr. Fortune?” Mr. Fortune then sat up, as he records, and took notice. Captain Cosdon burst out laughing, and departed, humming a stave of “Meet me to-night in Dreamland.” Mr. Fortune gazed at his hostess. He had not supposed that she could say anything so sensible. “Most crimes are perfect,” he said. “But how horrible! I should hate to be murdered and know there wasn’t a clue who did it.” “Oh, there’ll be a clue all right,” Reggie assured her. “Are you sure? And will you promise to catch my murderer, Mr. Fortune?” “Well, you know,” he considered her round amiable face, “if you were murdered it would be a case of art for art’s sake. That’s very rare. I was speakin’ scientifically. A perfect crime is a complete series of cause and effect. Where you have that, there’s always a clue, there is always evidence, and when you get to work on it the unknown quantities come out. Yes. Most crimes are perfect. But you must allow for chance. Sometimes the criminal is an idiot. That’s a nuisance. Sometimes he has a streak of luck and the crime is damaged before we find it, something has been washed out, a bit of it has been lost. It’s the imperfect crimes that give trouble.” “But how fascinating!” “Oh, Lord, no,” said Mr. Fortune.