"I saw her the other day," said Quarles, "and I quite endorse your opinion. She is charming, and I do not think she is the kind of woman to tell a deliberate falsehood. If Farrell had had an appointment with her I think she would have said so." "I am making no accusation against her," was the answer. "I was only sticking to the actual evidence." "And that does not tell us where Farrell went that day," said Quarles. "It seems strange that he did not meet any of the scores of people who knew him as he left the office that afternoon." "Undoubtedly he did meet many." "They didn't come forward to say they had seen him." "I can see no reason why they should do so. There was no question of fixing the time he left. I was able to give definite information on that point." "Well, we seem to have used up our facts," said Quarles, "and are forced to theorize." Delverton smiled. "You must not jump to the conclusion that I have failed," said the professor quickly. "I did not promise to tell you the name of the murderer to-night. Let me theorize for a few moments. You told me you believed that Farrell's tragic end had hastened your brother's death. Did your brother chance to come to the office that day?" "No." "Perhaps he came that night after you had left. I suppose you cannot bring evidence that he did not?" "No; but--" "Or it might have been with him that Farrell had an appointment that day, which was connected with some affair you were not intended to know anything about. That would account for his telling you a lie." "I assure you--" "Let me follow out my idea to the end," said Quarles, leaning over the table, and emphasizing his words by patting the cloth with his open hand. "Three years ago things were rather bad on the Stock Exchange, one or two men in the House were hammered, and several respected firms were shaky. Now supposing Farrell had been playing with the firm's money unknown to his partners, or perchance unknown only to one of them--yourself. Your brother may have--" "Really, Mr. Quarles, you are getting absurd." "I was going to say--" "Oh, please, let me stop you before you say anything more foolish," said Delverton. "At that time my brother was very ill and as weak as a rat. How could he have administered poison to Farrell?" "It requires no strength to administer poison, only subtlety," said Quarles. "A glass of wine, perhaps by your brother's bedside, and the thing would be accomplished. Or there is another alternative. Your brother may have been playing with the firm's credit, and Farrell may have found him out." "Any other alternative, Mr. Quarles? Your fertile brain must hold others." "Yes, one more, and two opinions which lead up to it," was the quick reply. Delverton laughed. "It is not so absurd as the others, I trust." "The two opinions may lead you to change your ideas concerning this mystery. First, I believe Kellner was made a partner because he knew too much."