"'For the past four years,' she told the police, 'my sister had an allowance of four pounds a week from a member of the aristocracy. I did not know much about her affairs, but I do know that she had a packet of letters on which she set great store. What these letters were I have not the slightest idea, nor do I know what Mary ultimately did with them. On one occasion, before she was actually settled at Hardacres, she met me in London and asked me to take care of this packet for her, and she told me then that they were very valuable. I also know that she and my brother Arthur had most heated arguments together on the subject of these letters. Arthur was always wanting her to give them up to him, and she always refused. On one occasion she told me that she could, if she wanted, sell that packet of letters for five thousand pounds. "Why on earth don't you?" I asked her. But she replied: "Oh, Arthur would only get the money out of me! It's better as it is."' "This story, as you may well imagine, gave food enough for gossip; at once a romance was woven of blackmail and drama of love and passion, whilst the name of a certain great lady in the neighbourhood, to whom Miss Clarke had been in the habit of paying mysterious weekly visits, already was on everybody's lips. "And then the climax came. By evening it had transpired that in Arthur Clarke's room at Hardacres, the detectives had found an old khaki tunic stuffed away at the bottom of a drawer, and in the pocket of the tunic the key of the locked parlour door. It was an officer's tunic, which had at some time had its buttons and badges taken off; its right sleeve was so torn that it was nearly out at its armhole; the cuff was all crumpled, as if it had been crushed in a damp, hot hand, and there was a small piece of the cloth torn clean out of it. And I will leave you to guess the importance of this fact--in the tightly-clenched hand of the murdered woman was found the small piece of khaki cloth which corresponded to a hair's-breadth with the missing bit in the sleeve of the tunic. "After that the man in the street shook his head and declared that Arthur Clarke was as good as hung already." §3 The Old Man in the Corner had drawn out of his capacious pocket a fresh piece of string. And now his claw-like fingers started to work on it with feverish intentness. I watched him, fascinated, well knowing that his keen mind was just as busy with the Hardacres mystery as were his hands in the fashioning of some intricate and complicated knot.