Her foot tattooed impatiently on the floor. "Please don't treat me as if I were a child, Mr. Foyle. Something has happened since yesterday morning. I demand to know what it is." Foyle was invariably gentle with women, and her insistent dignity rather amused than angered him. "Since you demand it," he said suavely, laying a scarcely perceptible stress on the word demand, "I will tell you. As the result of certain information, observation has been kept on Lady Eileen Meredith. She was followed yesterday to the advertisement offices of the _Daily Wire_, where she made inquiries respecting a certain cipher advertisement which was to appear in that paper. Failing to obtain what she wanted, she left a note warning some one in the following terms: 'The police know the cipher. Be very cautious. R. F. is acting with them.'" An angry flush swept across the girl's pale cheeks. "I know you have set your spies about me," she said scornfully. "I did not come here to ask you that. What----" "One moment. Let me finish. This morning Lady Eileen rose at an unfashionable hour--about four, to be exact--and went out to obtain a copy of the _Daily Wire_. Having deciphered the advertisement, and finding that it afforded no direct clue to Grell's whereabouts, she returned home and there came across a paragraph--which I will confess was inspired in this office--that set her wondering whether, after all, her lover was safe. She went out again--this time to Waterloo Bridge police station--and there made some inquiries----" Eileen had got to her feet. She was plainly angry. "I don't want to know how effective your spying on a harmless woman can be." "I am glad you admit it is effective," he answered quickly. "I wanted to bring that home to you. You cannot or will not understand in how perilous a situation you may find yourself if you go on playing with fire. There is no one else who has fuller sympathy with you or greater understanding of your feelings than I. Therefore I warn you. Do you know that merely on what you have done and are doing I should, were I certain that Grell was guilty, be justified in having you arrested as an accessory after the fact?" His voice became very grave. "If your conduct has not hampered this investigation, Lady Eileen, it has not been for want of effort. Take the warning of a man who wishes you well. For neither your position nor your friends will save you if ever you stand in my way. I shall do my duty, whatever the consequences." She was more impressed by his words and his tone than she would have cared to admit. But except that her face became a shade paler, she gave no indication that the warning touched her. Foyle had picked up his hat and stick. "You have not found him, then?" she cried. "Can it be doing you any harm to say what has happened?" "We have not found Grell--yet," he answered. "We found where he had been hiding, but he got away."