"But why not? If you're merely suspecting here and there without definite reason, why not include him on your list? And here's another thing. Whoever mixed that poison in the glass of water, afterward rinsed the glass and returned it to its place in the bath-room? This was either done at the time, that is, before the lady died, or later on, after death had ensued. In either case, it opens up a field of conjecture." "It doesn't with me," said Hardy, bluntly. "There's no room for conjecture. It simply piles up the proof against Miss Stuart, and all your skill and even your will can't get her off." A low moan was heard and a sound as of a falling body. Stone sprang to the door, and flinging it open, disclosed Pauline lying on the floor where she had just fallen. With a low exclamation, Stone picked her up and carried her to a couch. In a moment she sat up and cried, "What do you mean, Mr. Hardy? Do you think I killed Aunt Lucy?" "There, there, Miss Stuart, don't ask foolish questions," and Hardy, deeply embarrassed, stood at bay. It was one thing to assert his suspicions to Fleming Stone, and quite another to have them overheard by this beautiful and indignant girl. "How dare you!" Pauline went on. "I was at the door and I heard all you said. No, I am not ashamed of listening, I'm glad I did. Now I know what I have to fight against! And you, Mr. Stone, do you think me a murderer?" Pauline cringed not at all. She looked more like an avenging goddess, as she confronted the two men, and her blazing eyes and frowning face challenged their replies. "I do not, Miss Stuart," said Stone, quietly, but Pauline responded, "How do I know? If you did, you'd say you didn't! I have no friend, no one to stand up for me. I shall send for Carr. He will defend me." With a disdainful glance round, she left the room. The two men looked at one another. "Guilty," said Hardy. "Never!" said Stone, and then the two went their different ways. Hardy's way led to the Police Headquarters, and his report there, which included Stone's story of the tested glass, was heard with interest. He demanded Miss Stuart's immediate arrest, claiming that only she could have persuaded her aunt to swallow the poisoned draught. Inspector Brunt was not quite willing to order arrest, but he set machinery at work which he hoped would bring decisive results of some sort. It did. That same evening, Pauline went to Fleming Stone. The two were alone. Standing before him, in all her somewhat tragic beauty, Pauline asked: "You don't think me guilty, Mr. Stone?" He looked deep in the great, dark eyes that seemed to challenge his very soul, and after a moment's steady glance, he replied, "I know you are not, Miss Stuart." "Can you prove it?" "I hope to." "That means nothing. Are you sure you can?" Fleming Stone looked troubled. Never before in his career had he been unable to declare his surety of success; but with those compelling eyes upon him he couldn't deny a present doubt.