"_I_ know what he is, Rob, even better than you do. But cannot you see how this ties my hands, seals my lips?" Robert Cairn was silent, stupefied. "Give me time to see my way clearly, Rob. At the moment I cannot reconcile my duty and my conscience; I confess it. But give me time. If only as a move--as a matter of policy--keep in touch with Ferrara. You loathe him, I know; but we _must_ watch him! There are other interests--" "Myra!" Robert Cairn flushed hotly. "Yes, I see. I understand. By heavens, it's a hard part to play, but--" "Be advised by me, Rob. Meet stealth with stealth. My boy, we have seen strange ends come to those who stood in the path of someone. If you had studied the subjects that I have studied you would know that retribution, though slow, is inevitable. But be on your guard. I am taking precautions. We have an enemy; I do not pretend to deny it; and he fights with strange weapons. Perhaps I know something of those weapons, too, and I am adopting--certain measures. But one defence, and the one for you, is guile--stealth!" Robert Cairn spoke abruptly. "He is installed in palatial chambers in Piccadilly." "Have you been there?" "No." "Call upon him. Take the first opportunity to do so. Had it not been for your knowledge of certain things which happened in a top set at Oxford we might be groping in the dark now! You never liked Antony Ferrara--no men do; but you used to call upon him in college. Continue to call upon him, in town." Robert Cairn stood up, and lighted a cigarette. "Right you are, sir!" he said. "I'm glad I'm not alone in this thing! By the way, about--?" "Myra? For the present she remains at the house. There is Mrs. Hume, and all the old servants. We shall see what is to be done, later. You might run over and give her a look-up, though." "I will, sir! Good-bye." "Good-bye," said Dr. Cairn, and pressed the bell which summoned Marston to usher out the caller, and usher in the next patient. In Half-Moon Street, Robert Cairn stood irresolute; for he was one of those whose mental moods are physically reflected. He might call upon Myra Duquesne, in which event he would almost certainly be asked to stay to lunch; or he might call upon Antony Ferrara. He determined upon the latter, though less pleasant course.