I felt of my revolver at this bit of news, and was consoled to have the touch of it under my hand. “I didn't see him,” I said. “Keep the child between us, and shoot anybody who tries to stop us or to climb into the hack. I must read my orders.” “All right, sir,” said Wainwright, making the child comfortable between us. I tore open the envelope and drew forth the scented paper with its familiar, firm, yet delicate handwriting, and read the words: “Take the train with your men for Livermore. Await orders at the hotel. Protect the boy at all hazards.” Inclosed in the sheet were gold-notes to the value of five hundred dollars--a thoughtful detail for which I was grateful at the outset of such an expedition. I thrust the money into my pocket and pondered upon the letter, wondering where Livermore might be. My knowledge of the geography of California was exceedingly scant. I knew that Oakland lay across the bay and that Brooklyn lay close by, a part of Oakland. I remembered a dinner at Sacramento, and knew Los Angeles on the map. Further than this my ideas were of the most hazy character, and Livermore was nowhere to be found in my geographical memory. I had some thought of questioning Wainwright, who was busy trying to make friends with the child, but reflecting that I might be supposed to know all about it I was silent. Wainwright's efforts to get the child to speak were without success. The little thing might from its size have been five years old, but it was dumb--frightened, as I supposed, by the strangeness of the situation, and would speak no word. This, then, was the mysterious boy whose fate was linked so closely with my own; about whose body battled the hirelings of Doddridge Knapp and of my unknown employer; for whom murder had been done, and for whom perhaps many now living were to give up their lives. Who was he? Whence had he come? What interests were bound up in his life? Why was his body the focus of plot and counterplot, and its possession disputed with a fierce earnestness that stopped at no crime? Perhaps, could he be got to talk, the key of the mystery might be put in my hands. Out of the mouth of the babe I might learn the secret that had racked my brain for days and weeks. And why was he put thus in my charge? What was I to do with him? Whither was I to carry him? I reproached myself that I had not stopped the Unknown to ask more questions, to get more light on the duties that were expected of me. But the hack on a sudden pulled up, and I saw that we were before the long, low, ugly wooden building that sat square across Market Street as the gateway to San Francisco through which the tide of travel must pass to and from the Golden City. “Look out on both sides, Wainwright,” I cautioned. “You carry the boy and I'll shoot if there's any trouble. See that you keep him safe.”