"I presented," he said, "a certain contingency to you, the contingency of my leaving this house, and you have been delightfully explicit as to the course you would pursue. But, my dear sir, crediting myself with a species of occult power, which you appear ready to grant to me, might it not be in my power to vanish, to disappear from your sight the moment the policeman you would summons attempted to lay hands upon me?" "I must chance that," I said. "Good. Nothing of the sort will occur, I promise. I cannot carry on my pursuit as a Shadow. The idea of leaving the house did occur to me; I banish it. Well, then, suppose I remain here; suppose I put an end to this discussion; suppose I go to bed. To all your vapourings, suppose I say, 'Go to the devil!' Why on earth do you stare at me so? It is a common saying, and the awful consequences of such a journey are seldom thought of. I repeat, I say to you, 'Go to the devil!' What, then?" "I still could summon a policeman," I said; "but even if I postponed that step or you managed to escape from me, I have a talent which, now that it occurs to me, I shall immediately press into my service." "Enlighten me." I took from my pocket some letters, and tore from them three blank leaves, upon which I set to work with pencil. My task occupied me ten minutes and more, during which time Devlin, sitting back in his chair, watched me with an expression of intense amusement in his face. When I had finished I handed him one of the blank leaves. "My portrait!" he exclaimed. "I am an artist myself, as you have seen in Mrs. Lemon's parlour. This picture is the very image of me!" "There is no mistaking it," I said complacently. "It will insure recognition." "In what way do you propose to turn it to advantage, in the event of my being contumacious?" "You have doubtless," I said, "noted the changes that have taken place in the life of civilised cities?" "Excellent," he said. "My dear sir, you compel my admiration; you are altogether so different a person from the simpleton who lies shaking in his bed on the floor below. You have brain power. My worthy landlord and partner would have as well fulfilled his destiny had he been a mouse. The changes that have taken place! Ah, what changes have I not seen, say, in the course of the last thousand years!" And here he laughed loud and long. "But proceed, my dear sir, proceed. How do these changes affect me in the matter we are now considering?" "There was a time----" "Really, like the beginning of a fairy story," he interposed. "When public opinion was of small weight, whereas now it is the most important factor in social affairs." "Lucidly put. I listen to you with interest." "The penny newspaper," I observed sagely, "is a mighty engine." "You speak with the wisdom of a platitudinarian." "It enlists itself in the cause of justice, and frequently plays, to a serviceable end, the part of a detective. You may remember the case of Leroy."