I had occasion to be a little precise in my particulars, and it being still light enough, I remembered the red chalk in my pocket, and drew the hand on the wall. "Here, you see, is the hand", I said, as I explained its true meaning, "note where the thumb issues from between the first and second fingers", and I would have gone on, and had applied the chalk to the wall to continue my diagram, when he struck my hand down much to my surprise. "No, no," he said, "I do not want all that. And this place is not retired enough; let us walk on, and do you explain everything to me minutely." I complied readily enough, and he led me away choosing the most unfrequented by-ways, while I drove in the plan of the hidden house word by word. Once or twice as I raised my eyes I caught Vivian looking strangely about him; he seemed to give a quick glint up and down, and glance at the houses; and there was a furtive and anxious air about him that displeased me. "Let us walk on to the north," he said at length, "we shall come to some pleasant lanes where we can discuss these matters, quietly; my night's rest is at your service." I declined, on the pretext that I could not dispense with my visit to Oxford Street, and went on till he understood every turning and winding and the minutest detail as well as myself. We had returned on our footsteps, and stood again in the dark passage, just where I had drawn the red hand on the wall, for I recognized the vague shape of the trees whose branches hung above us. "We have come back to our starting-point," I said; "I almost think I could put my finger on the wall where I drew the hand. And I am sure you could put your finger on the mystic hand in the hills as well as I. Remember between stream and stone."

'I was bending down, peering at what I thought must be my drawing, when I heard a sharp hiss of breath, and started up, and saw Vivian with his arm uplifted and a bare blade in his hand, and death threatening in his eyes. In sheer self-defence I caught at the flint weapon in my pocket, and dashed at him in blind fear of my life, and the next instant he lay dead upon the stones.

'I think that is all,' Mr. Selby continued after a pause, 'and it only remains for me to say to you, Mr. Dyson, that I cannot conceive what means enabled you to run me down.'

'I followed many indications,' said Dyson, 'and I am bound to disclaim all credit for acuteness, as I have made several gross blunders. Your celestial cypher did not, I confess, give me much trouble; I saw at once that terms of astronomy were substituted for common words and phrases. You had lost something black, or something black had been stolen from you; a celestial globe is a copy of the heavens, so I knew you meant you had a copy of what you had lost. Obviously, then, I came to the conclusion that you had lost a black object with characters or symbols written or inscribed on it, since the object in question certainly contained valuable information and all information must be written or pictured. "Our old orbit remains unchanged"; evidently our old course or arrangement. "The number of my sign" must mean the number of my house, the allusion being to the signs of the zodiac. I need not say that "the other side of the moon" can stand for nothing but some place where no one else has been; and "some other house" is some other place of meeting, the "house" being the old term "house of the heavens." Then my next step was to find the "black heaven" that had been stolen, and by a process of exhaustion I did so.'

'You have got the tablet?'

'Certainly. And on the back of it, on the slip of paper you have mentioned, I read 'inroad,' which puzzled me a good deal, till I thought of Grey's Inn Road; you forgot the second n. "Stony-hearted step——" immediately suggested the phrase of De Quincey you have alluded to; and I made the wild but correct shot, that you were a man who lived in or near the Gray's Inn Road, and had the habit of walking in Oxford Street, for you remember how the opium-eater dwells on his wearying promenades along that thoroughfare. On the theory of improbability, which I have explained to my friend here, I concluded that occasionally, at all events, you would choose the way by Guildford Street, Russell Square, and Great Russell Street, and I knew that if I watched long enough I should see you. But how was I to recognize my man? I noticed the screever opposite my rooms, and got him to draw every day a large hand, in the gesture so familiar to us all, upon the wall behind him. I thought that when the unknown person did pass he would certainly betray some emotion at the sudden vision of the sign, to him the most terrible of symbols. You know the rest. Ah, as to catching you an hour later, that was, I confess, a refinement. From the fact of your having occupied the same rooms for so many years, in a neighbourhood moreover where lodgers are migratory to excess, I drew the conclusion that you were a man of fixed habit, and I was sure that after you had got over your fright you would return for the walk down Oxford Street. You did, by way of New Oxford Street, and I was waiting at the corner.'

'Your conclusions are admirable,' said Mr. Selby. 'I may tell you that I had my stroll down Oxford Street the night Sir Thomas Vivian died. And I think that is all I have to say.'

'Scarcely,' said Dyson. 'How about the treasure?'

'I had rather we did not speak of that,' said Mr.