DOCTOR. [_Slightly encouraged, but speaking very carefully._] Nevertheless, mental excitement is necessarily an element of importance in physiological troubles, and your triumphs this evening were really so extraordinary that I cannot pretend to dismiss them from my patient's case. He is at present in a state somewhat analogous to delirium, but in which he can still partially ask and answer questions. The question he continually asks is how you managed to do your last trick. CONJURER. Ah! My last trick! DOCTOR. Now I was wondering whether we could make any arrangement which would be fair to you in the matter. Would it be possible for you to give me in confidence the means of satisfying this--this fixed idea he seems to have got. [_He hesitates again, and picks his words more slowly._] This special condition of semi-delirious disputation is a rare one, and connected in my experience with rather unfortunate cases. CONJURER. [_Looking at him steadily._] Do you mean he is going mad? DOCTOR. [_Rather taken aback for the first time._] Really, you ask me an unfair question. I could not explain the fine shades of these things to a layman. And even if--if what you suggest were so, I should have to regard it as a professional secret. CONJURER. [_Still looking at him._] And don't you think you ask me a rather unfair question, Dr. Grimthorpe? If yours is a professional secret, is not mine a professional secret too? If you may hide truth from the world, why may not I? You don't tell your tricks. I don't tell my tricks. DOCTOR. [_With some heat._] Ours are not tricks. CONJURER. [_Reflectively._] Ah, no one can be sure of that till the tricks are told. DOCTOR. But the public can see a doctor's cures as plain as.... CONJURER. Yes. As plain as they saw the red lamp over his door this evening. DOCTOR. [_After a pause._] Your secret, of course, would be strictly kept by every one involved. CONJURER. Oh, of course. People in delirium always keep secrets strictly. DOCTOR. No one sees the patient but his sister and myself. CONJURER. [_Starts slightly._] Yes, his sister. Is she very anxious? DOCTOR. [_In a lower voice._] What would you suppose? [CONJURER _throws himself into the chair, his cloak slipping back from his evening dress. He ruminates for a short space and then speaks._ CONJURER. Doctor, there are about a thousand reasons why I should not tell you how I really did that trick. But one will suffice, because it is the most practical of all. DOCTOR. Well? And why shouldn't you tell me? CONJURER. Because you wouldn't believe me if I did. [_A silence, the_ DOCTOR _looking at him curiously._ [_Enter the_ DUKE _with papers in his hand. His usual gaiety of manner has a rather forced air, owing to the fact that by some vague sick-room associations he walks as if on tip-toe and begins to speak in a sort of loud or shrill whisper. This he fortunately forgets and falls into his more natural voice._