He cast the light of his lamp upon the stool for a moment, while I did as he bade me. Standing there, I found that I was tall enough to look through; but the narrow pane which formed the window was thickly covered with size, or some opaque integument. All I could tell was, that the space beyond was lighted. "I know you can’t see now," he said, as I came down despairing, "but you shall see by and by. The fools who were here before sized the glass on the wrong side, and this lot, though much sharper, have not corrected the error. They keep that window for escape in the last resort. Now take this bottle and this camel’s-hair brush; it will make the glass transparent without the smallest noise. The men are not there yet. We could easily rub it clear now, but they will examine it. When the time comes, use the liquid most carefully and lightly, and don’t spread it higher than an inch from the bottom of the frame. The lights are at this end; the shadow of the sill will allow you just an inch." "And how far may I go horizontally?" "The whole length of the glass, to command as much view as possible. The effect will pass in three or four minutes, but you must not do it again. If you do, the glass will fly, and you will be in their hands. Desperate men they are, and though I shall be near, I might be too late to save you. See all you can, to be able to swear to them all." "How shall I know the one?" "I cannot tell you. I must leave it to your instinct, or your intuition. I only know myself that he is one of the four. My information, such as it is, was obtained very oddly, and I trust to this night’s work to make it more precise. One thing more: No noise, if you value your life. Keep the bottle stopped. Don’t let the stuff drop on you; don’t put your eyes to it, or it will blind you for ever. There is very little of it, because it is so deadly." "When shall I do it?" "In one hour from this time. Take this repeater. I have shown you how to use it. Look well at it now, while you have the light." I looked at the watch; it was nearly midnight. "Am I to be left in the dark--all in the dark here, by myself?" "Yes. I must be seen elsewhere, or the whole thing fails. They know me even in this dress, and they watch me as I do them. But for to-night I believe I have misled them. When it is over, wait here till I come for you, or the little girl you saw." "Oh! I wish I had never come; and all so vague and indecisive!" "You can go back now, if you please; though ever that would be dangerous." "I will not go back. No doubt I shall know him. When will you secure him?"