The two went to the well and lifted the hatch door. As they did so, Oakes held a lighted match inside one end of the tunnel. It blew strongly toward us; the air was rushing in, and we knew the passage led to the opening. We heard their voices calling to us. Dr. Moore spoke. "Oakes, you shall _not_ go in there; you have done enough to-day; you are a wounded man." I caught up the lantern and my revolver, and Moore followed. "Hold on!" said Oakes. "You are in the most dangerous part; don't be rash. Here, Stone, you go first--and Moore, you follow about ten feet behind, without a light, in order that you may be undetected. Take matches. I'll stay here with the taper, and watch. When you get to the other end, don't go up the steps leading to the ground until both Mike and Cook show themselves. We know nothing about them, you know. Be cautious. The man we want went out this way, whoever he is." I threw the light ahead and advanced some ten feet. I heard Moore following. "Careful!" said he in a whisper. Again I threw the light ahead, and beheld only the walls of the square tunnel. I could hear the breathing of Moore behind me. I knocked on the wall here and there with my revolver; it rang true and solid. We gradually advanced until we beheld the daylight and saw the men waiting at the head of the stone steps. I ascended. Moore took the lantern and called back to Oakes, addressing him as Clark. In a moment he came. "Stay where you are, Stone," said he to me. "Come here, Mike." Mike descended willingly enough. I watched Cook and looked all around. "Open that door." Oakes pointed to a little wooden opening in the side of the stairs. Mike obeyed, but instantly closed it again with a bang. "A man!" said he. Oakes and Moore levelled their revolvers. "Come out," said the detective, "or take the consequences. I shall shoot." Mike opened the door again, hiding his figure behind it for protection as it swung out. I expected to see some one shot, but Moore threw the light in, and instantly Oakes dived forward into the alcove of stone. We could hear him chuckle. Cook, at my side, was standing on one leg in his excitement. Then Dr. Moore burst into laughter. "What is it? What's the matter?" I cried. I could not see very well, and ran half-way down. Oakes was standing beside Moore, trying to look grave. In his hand was a red paper mask and a long black robe! O'Brien looked on, his eyes twinkling, but his face serious. "I'm thinking it's lucky, Mr. Clark, sorr, that ye saved yer ammunition," said he. "Yes," retorted Oakes, "and it's still more fortunate you're a good actor." O'Brien's somewhat insolent manner changed instantly to one of civility, and Oakes turned to us. "No wonder some said there was a woman in this affair." Then he ordered the hatch door nailed down, and handed the things to me. "Please take these upstairs, Stone; we must investigate this more fully," and we withdrew to discuss our findings.