The doctor's countenance wore a puzzled expression as he spoke; his eyes a far-away look, just as though he did not see his own theory clearly. Mr. Tamlyn's face changed: the astonishment, the alarm, the dismay depicted on it gave place suddenly to relief. "It cannot be, Arnold. Rely upon it you are mistaken. Who would harm her?" "No one that I know of; no suspicious person is about her to do it," replied Dr. Knox. "And there lies the puzzle. I suppose she does not take anything herself? Opium, say?" "Good Heavens, no," warmly spoke old Tamlyn. "No woman living is less likely to do that than Lady Jenkins." "Less likely than she _was_. But you know yourself how unaccountably she has changed." "She does not take opium or any other drug. I could stake my word upon it, Arnold." "Then it is being given to her--at least, I think so. If not, her state is to me inexplicable. Mind you, Mr. Tamlyn, not a breath of this must transpire beyond our two selves," urged Dr. Knox, his tone and his gaze at his senior partner alike impressively earnest. "If anything is wrong, it is being wilfully and covertly enacted; and our only chance of tracing it home is to conceal our suspicion of it." "I beg your pardon, Dr. Knox," I interrupted at this juncture, the notion, suddenly flashing into my mind, that he was unaware of my presence, sending me hot all over; "did you know I was here?" They both turned to me, and Dr. Knox's confused start was a sufficient answer. "You heard all I said, Johnny Ludlow?" spoke Dr. Knox. "All. I am very sorry." "Well, it cannot be helped now. You will not let it transpire?" "That I certainly will not." "We shall have to take you into our confidence--to include you in the plot," said Arnold Knox, with a smile. "I believe we might have a less trustworthy adherent." "You could not have one more true." "Right, Johnny," added Mr. Tamlyn. "But I do hope Dr. Knox is mistaken. I think you must be, Arnold. What are your grounds for this new theory?" "I don't tell you that it is quite new," replied Dr. Knox. "A faint idea of it has been floating in my mind for some little time. As to grounds, I have no more to go upon than you have had. Lady Jenkins is in a state that we do not understand; neither you nor I can fathom what is amiss with her; and I need not point out that such a condition of things is unsatisfactory to a medical man, and sets him thinking." "I am sure I have not been able to tell what it is that ails her," concurred old Tamlyn, in a helpless kind of tone. "She seems always to be in a lethargy, more or less; to possess no proper self-will; to have parted, so to say, with all her interest in life."