"Yes; stand by the door. If you hear anyone come, bolt it on the inside, and we can get away as we came. If they come the other way, we can get through the door if our job is done, or hide behind these window curtains if it is not. Do you understand?" I nodded and stood by the door. My first feeling of fear had passed away, and I thrilled now with a keener zest than I had ever enjoyed when we were the defenders of the law instead of its defiers. The high object of our mission, the consciousness that it was unselfish and chivalrous, the villainous character of our opponent, all added to the sporting interest of the adventure. Far from feeling guilty, I rejoiced and exulted in our dangers. With a glow of admiration I watched Holmes unrolling his case of instruments and choosing his tool with the calm, scientific accuracy of a surgeon who performs a delicate operation. I knew that the opening of safes was a particular hobby with him, and I understood the joy which it gave him to be confronted with this green and gold monster, the dragon which held in its maw the reputations of many fair ladies. Turning up the cuffs of his dress-coat--he had placed his overcoat on a chair--Holmes laid out two drills, a jemmy, and several skeleton keys. I stood at the centre door with my eyes glancing at each of the others, ready for any emergency; though, indeed, my plans were somewhat vague as to what I should do if we were interrupted. For half an hour Holmes worked with concentrated energy, laying down one tool, picking up another, handling each with the strength and delicacy of the trained mechanic. Finally I heard a click, the broad green door swung open, and inside I had a glimpse of a number of paper packets, each tied, sealed, and inscribed. Holmes picked one out, but it was hard to read by the flickering fire, and he drew out his little dark lantern, for it was too dangerous, with Milverton in the next room, to switch on the electric light. Suddenly I saw him halt, listen intently, and then in an instant he had swung the door of the safe to, picked up his coat, stuffed his tools into the pockets, and darted behind the window curtain, motioning me to do the same. [Illustration: "HE STOOD WITH SLANTING HEAD LISTENING INTENTLY."]