"Unhappily, I do not know--not yet, at least, but I shall do so some day." She had risen now, and was standing before him pale and erect. The long white peignoir that she wore clung to her delicate, supple figure, making her look unusually tall; and she appeared to her lover like some ancient classic figure vowing vengeance on the guilty. As she stood thus, with a fixed look of certainty on her face, and prophesied that some day she should know the man who had done this deed, she might have been Cassandra come back to the world again. "His face was shrouded," she went on, "as all murderers shroud their faces, I think; but his form I knew. I am thinking--I have thought and thought for hours by day and night--where I have seen that form before. And in some unexpected moment remembrance will come to me." "Even though it does, I am afraid the remembrance will hardly bring the murderer to justice," Penlyn said. "A man can scarcely be convicted of a reality by a dream." "No," she answered, "he cannot, I suppose. But it will tell me who that man is, and then----and then----" "And then?" Penlyn interrupted. "And then, if I can compass it, his life shall be subjected to such inspection, his every action of the past examined, every action of the present watched, that at last he shall stand discovered before the world!" She paused a moment, and again she looked fixedly at him, and then she said: "You are my future husband; do you know what I require of you before I become your wife?" "Love and fidelity, Ida, is it not? And have you not that?" "Yes," she answered, "but that fidelity must be tried by a strong test. You must go hand in hand with me in my search for his murderer, you must never falter in your determination to find him. Will you do this out of your love for me?" "I will do it," Penlyn answered, "out of my love for you." She held out her hand--cold as marble--to him, and he took it and kissed it. But as he did so, he muttered to himself: "If she could only know; if she could only know." Again the impulse was on his lips to tell her of the strange relationship there was between him and the dead man, and again he let the impulse go. In the excitement of her mind would she not instantly conclude that he was the slayer of his dead brother, of the man who had suddenly come between him and everything he prized in the world? And, to support him in his weakness, was there not the letter of that dead brother enjoining secrecy? So he held his peace! "I will do it," he said, "out of my love for you; but, forgive me, are you not taking an unusual interest in him, sad as his death was?"