"It was a dog!" the doctor felt sure. To Rolla, however, the animal was even more significant. She exclaimed about it in a way which confirmed the doctor's guess. On she went at a faster rate, plainly excited and hopeful of seeing something further that she could recognize. She found it in a hurry. Reaching the end of one block of the ruins, she turned the corner and started to follow the cross street. Whereupon she stopped short, to gaze in consternation at a line of something whitish which stretched from one side of the "street" to the other. It was a line of human skeletons. There were perhaps two hundred in the lot, piled one on top of the other, and forming a low barrier across the pavement. To Rolla the thing was simply terrible, and totally without explanation. To the people on the earth, it suggested a formation of troops, shot down in their tracks and left where they had fallen. The doctor would have given a year of his life if only Rolla had had the courage to examine the bones; there might have been bullet holes, or other evidence of how they had met their death. The Sanusian chose rather to back carefully away from the spot. She walked hurriedly up the street she had just left, and before going another block came across two skeletons lying right in the middle of the street. A little farther on, and she began to find skeletons on every hand. Moreover--and this is especially significant--the buildings in this locality showed a great many gaps and holes in their walls, such as might have been made by shell-fire. This made it easier to understand something else. Every few yards or so the explorer found a large heap of rust in the gutter, or what had once been the gutter. These heaps had little or no shape; yet the doctor fancied he could detect certain resemblances to things he had seen before, and shortly declared that they were the remains of motors. "Can't say whether they were aircraft or autos, of course," he added, "but those things were certainly machines." Later, Rolla paid more attention to them, and the doctor positively identified them as former motor-cars. The sun had gone down. It was still quite light, of course; darkness would not come for a couple of hours. Rolla munched on what food she had, and pressed on through the ruins. She saw skeletons and rusted engines everywhere, and once passed a rounded heap of rust which looked like nothing so much as a large cannon shell. Had the place been the scene of a battle? Just when she had got rather accustomed to the place and was feeling more or less at her ease, she stopped short. At the same time the doctor himself fairly jumped in his chair. Somewhere, right near at hand, on one of the larger structures, a bell began to ring! It clanged loudly and confidently, giving out perhaps thirty strokes before it stopped. The stillness which followed was pretty painful. In a moment, however, it was broken as effectively as any silence can be broken.