I did not answer. It was indeed too solemn a thing for words, this watching from the darkness while an invisible death, let loose by our own hands, stole down upon our complacent enemies.
A few moments more we watched—and still the scene before us showed no change. Then, abruptly, the lights seemed to waver; some of the beams swung hurriedly to and fro, then remained motionless in unusual positions, as though the men at their levers in sudden panic had abandoned them.
My heart was beating violently. What hidden tragedy was being enacted behind that silent barrier of light? I shuddered as my imagination conjured up hideous pictures of that unseen death that now must be stalking about those city streets, entering those homes, polluting the air with its stifling, noisome breath, and that even at this distance seemed clutching at my own lungs.
I suppose the whole thing did last only a moment. There was little in what we saw of significance had we not known. But we did know—and the knowledge left us trembling and unnerved.
I leaped to my feet, pulling Miela after me, and in a few moments more we were back beside the projector we had left with Mercer and Anina. Suddenly a white shape appeared in the sky over the city. It passed perilously close above the shattered light‑barrage and came sailing out in our direction.
Mercer jumped for the projector, but I was nearer, and in a moment I had flashed it on.
"It's Tao!" Mercer shouted. "He—"
It was one of Tao's interplanetary vehicles, rising slowly in a great arc above us. I swung our light‑beams upward; it swept across the sky and fell upon the white shape; the thing seemed to poise in its flight, as though held by the little red circle of light that fastened upon it, boring its way in. Then, slowly at first, it fell; faster and faster it dropped, until it struck the ground with a great crash—the first and only sound of all this soundless warfare.
It was three days before the great sulphur deposit we had ignited burned itself out. The lights of the city had all died away, and blackness such as I never hope to experience again settled down upon the scene.