The effect on my mind was so strong that, at last, I said to myself: “I shall never know peace again until I am certain that M. Darzac is not Larsan. And I shall take means to make myself certain, one way or the other, on the first occasion.” Yes, but how? Pull his beard off? If my suspicion was baseless, he would take me for a madman, or else he would guess what I was thinking of and such a knowledge would add yet another to the load of misfortunes, already too heavy for him to bear. Only this misery was lacking to him still--to know that he was suspected of being Larsan. Suddenly I threw off the bedclothes, jumped up and cried almost aloud: “Australia!” An episode had returned to my mind of which I have spoken at the beginning of this story. The reader may remember that, at the time of the accident in the laboratory, I had accompanied M. Robert Darzac to a druggist. While his injuries were being attended to, he had been obliged to remove his study coat, and the sleeve of his shirt had fallen back, leaving his arm bare through the entire session with the druggist, and placing in full view just above the right elbow, a large birth mark, the shape of which resembled that of Australia as it appears on the maps in the geographies. Mentally, while the chemist was at work, I had amused myself by trying to locate upon the arm in the positions which they occupied on an actual map, the cities of Melbourne, Sydney, Adelaide, etc.; and directly beneath this large mark, there was another smaller one which was situated like the country known as Tasmania. And when, by any chance, the thought of that accident had happened to recur to my mind, I had always thought of the half hour at the chemist’s and the birthmark shaped like the outlines of Australia. And in this sleepless night, it was the thought of Australia that came to me. Seated on the edge of my bed, I had scarcely had time to congratulate myself upon having found a means to prove decisively the identity of Robert Darzac and to try to devise some way of bringing it to an immediate test, when a singular sound made me prick up my ears. The sound was repeated--one would have said that gravel was cracking beneath slow and cautious footsteps. Breathless, I hurried to my door and, with my ear at the keyhole, I listened. Silence for a moment and then once more the same sound--footsteps, beyond a doubt. Someone was now ascending the staircase--and someone who desired his presence to be unknown. I thought of the shadow which I had believed I saw as I was entering the Court of the Bold--whose could this shadow be and what was it doing on the staircase? Was it coming up or going down?