From the photographer’s studio in which he found himself, nothing but a draw-bolt kept him from an outside hallway. Making sure that the building was deserted, and everything safe, he worked his way slowly down, like a diver, stair by stair, to the basement. Here he made a careful study of the little tunnel of electric wires at the back of the lower hall, probing, testing, measuring, and finally, with cool deliberation, “bridging” the necessary portion of the burglar-alarm connection, which he knew to be operated on a closed circuit. This circuit he diverted as a miner diverts a troublesome stream. Then, holding before him his little two-candle incandescent lamp, scarcely bigger than his thumb nail, he groped toward the iron covered door that divided one-half of the building from the other. Here he directed his thin shaft of light into the crack between the heavy door and its studding, and his squinting eyes made out the iron lock-bar that held him out. From his vest pocket, where they stood in a row like glimmering pencils, he took out one of the slim steel drills, adjusted it noiselessly in the drill-flange, and snapped shut his switch. There was the quick spit of a blue spark, and of a sudden, the inanimate thing of steel throbbed and sang and quivered with mysterious life. As he glanced down at it, in its fierce revolutions, he realized that once more he had for an accomplice that old-time silent, and ever-ready assistant which for years had been a well-tested and faithful friend. The mere companionship with so familiar a force brought back to him his waning confidence. He forced the whirling drill through the door-crack and in against the bar. It ate through the soft iron as though it had been a bar of cheese. Eight carefully placed perforations, side by side, had severed the end of the lockshaft. He shut off the current, confidently, and swung open the heavy door. The falling piece of iron made a little tinkle of sound on the cement flooring, then all was silence again. He had at least, he told himself, captured the enemy’s outposts. Cautiously he felt his way across the warm cellar, up the steps, and at last faced his one definite barrier, the door of solid steel, abutted by even more solid masonry. The builders of that door had done their best to make it forbidding to men of his turn of mind, Durkin ruminated, as he felt and sounded and tested despondently over its taciturn painted surface. He studied the hinges carefully, through his tiny lamp. They were impregnable. As he had surmised, his only way was to cut out, inch by inch, the three heavy steel shafts, or bolt-bars, which slipped and fitted into steel casings also, apparently, embedded in solid masonry.