"Perhaps," and her gray eyes searched his face, "you too think so. But no matter. I tell you, and I know, that he did not do this thing."
There was a moment's silence, then Ashton-Kirk said, quietly:
"Then who did?"
She gestured with both hands.
"Because I say that I know that he did not," she replied, "does it follow that I must know who did?" She waited for an answer, but as none came, she went on: "You have heard that Philip Warwick and Stella Corbin were to be married? I thought so. He is a very boyish fellow; he was proud of her and told every one. I was glad when I heard it, for I thought them well mated. But Simon was not pleased; the young man perhaps would not follow where he led; at any rate he disliked him. They quite frequently had high words; but Mr. Warwick never allowed himself to go too far in his resentment—at least never until lately. The day that you first visited the house, they almost came to blows; and on the night that Simon was killed, he actually struck his secretary."
"This was not told to the police," said the secret agent. "Why?"
"I was the only one that saw it," said the old woman, "and I did not tell of it because I knew that it would only make them suspect the young man all the more."
"Go on," said Ashton-Kirk.
"This is how I came to be a witness to what passed between them. I had gone to the front door to answer a ring, but it was only a person to inquire about some one who had lately left a house across the street. As I closed the door, I saw that of the library ajar; and through the opening I saw Dr. Morse and Mr. Warwick standing facing each other.
"'Very well, then,' Mr. Warwick was saying, 'it shall be done in spite of you.'