“This is depressing,” said Luella, with a touch on my arm. “Let's go on.” “Turn to the right there,” Corson called out, as we led the way while he was explaining to Mr. Carter the method of smoking. “Let us get where there is some air,” said Luella. “This odor is sickening.” We hastened on, and, turning to the right, soon came on two passages. One led up a stair, hidden by a turn after half a dozen steps. The other stretched fifty or seventy-five feet before us, and an oil lamp on a bracket at the farther end gave a smoky light to the passage and to a mean little court on which it appeared to open. “We had better wait for the rest,” said Luella cautiously. As she spoke, one of the doors toward the farther end of the passage swung back, and a tall heavy figure came out. My heart gave a great bound, and I felt without realizing it at the moment, that Luella clutched my arm fiercely. In the dim light the figure was the figure of the Wolf, the head was the head of the Wolf, and though no light shone upon it, the face was the face of the Wolf, livid, distorted with anger, fear and brutal passions. “Doddridge Knapp!” I exclaimed, and gave a step forward. It flashed on me that one mystery was explained. I had found out why the Doddridge Knapp of plot and counterplot, and the Doddridge Knapp who was the generous and confidential employer, could dwell in the same body. The King of the Street was a slave of the Black Smoke, and, like many another, went mad under the influence of the subtle drug. As I moved forward, Luella clung to me and gave a low cry. The Wolf figure threw one malignant look at us and was gone. “Take me home, oh, take me home!” cried Luella in low suppressed tones, trembling and half-falling. I put my arm about her to support her. “What is it?” I asked. She leaned upon me for one moment, and the black walls and gloomy passage became a palace filled with flowers. Then her strength and resolution returned, and she shook herself free. “Come; let us go back to the others,” she said a little unsteadily. “We should not have left them.” “Certainly,” I replied. “They ought to be here by this time.” But as we turned, a sudden cry sounded as of an order given. There was a bang of wood and a click of metal, and, as we looked, we saw that unseen hands had closed the way to our return. A barred and iron-bound door was locked in our faces. CHAPTER XVIII THE BATTLE IN THE MAZE