We passed into the great building's marble entrance hall, a place of dim shadows, through which we stumbled over prostrate dead. We went quickly through the looted, wrecked rooms that had been the luxurious shops of its first level. Then the stairs, and we were going upward, level after level, searching through the immense building's numberless offices and rooms. In one or two were dead, and some had been wrecked, but in none, in no part of the building, it seemed, were any of the ape-like throngs. That seemed encouraging, somehow, and with beating hearts we pressed on upward. Level after level. We were high in the immense building; its floors here were smaller of extent because of its pyramidal form. Yet there was no sound from the shadows about us, no sign of what we sought. Despair was growing in us, for we were high in the great tower that was the building's uppermost part, and had found nothing. Through the shadowy halls we pressed still, and through the silent rooms lit with the gold of the westward-swinging sun. But as we moved up the narrow stair toward the last and highest level of the great tower, something flamed in Ferson's eyes as in mine. A sound had come from above to our ears, a steady, slow clicking as of a great clock. Pistols in hand, we moved up, found ourselves in a small hall at the tower's side. The unused elevator-shaft was beside us, and the stairs that led to the roof. But before us was the single door that gave access, apparently, to the whole space of the tower's uppermost level. And from behind it came the slow clicking to our ears! As one we crossed the hall toward that door. Ferson's hand on its knob turned slowly, and slowly, astoundingly, the door swung open. Our pistols lowered for the moment in our amazement, we stepped through, stopped. A dozen feet before us stood Grant, a heavy automatic in his hand trained upon us. Silence. In it Grant's eyes held ours. His dark-browed powerful face was lit with unholy triumph, with sardonic exultation. I saw that before us was the whole space of the tower's highest level, thrown into one great room. Huge black-cased and powerful batteries were ranged upon each other in scores at one side of the room. Armored cables led from them through incalculable generators and transformers to a great object at the big room's center. It was like a giant searchlight, a dozen feet or more in diameter, swung in a frame resembling gimbals, so that it could be turned in any direction. The twelve-foot disk inside it glowed silently with white light, and the great thing was turned to face exactly the sinking sun westward. It was slowly following the descending sun, turning slowly under the action of a great clock-mechanism, whose clicking was loud in our ears still. Grant, Ferson and I----we were silent there in the room, all motionless, until Grant spoke. His voice was metallic, controlled, mocking.