The girl's tense fears, strong enough to make her come here, after midnight, to his laboratory, emphasized Sam's own private anxieties.
"I haven't been doing much, Honey," he told her hesitantly, and not too convincingly. "You'd better just run along home to bed. Research causes accidents once in a while. I'll get everything straightened out all right."
But in the reflected rays of the flashlight, the girl's face and eyes were determined.
"I won't go, Sam," she said very definitely, "until I find out that everything is all right. First place, you're hurt, and I'd be stubborn for your sake. But there's more. That glow in the sky. That smell of ozone—not only here, but everywhere here.... What does it all mean, Sam?"
Conway looked nervously toward the heavens. Yes, he could see a halo of light, sure enough. He had thought it was only the diffusion of starshine by the moisture in the atmosphere. Now he knew better. It was a little too bright and too low to be an aurora. It could be like an aurora, of course, something electrical and yet not quite the real, normal thing.
The breeze outside bore a slight yet unmistakable pungence of ozone too. It was just as Ellen had said. The gas was not only in the lab. It was here, too, as though all the atmosphere in the neighborhood had been affected by some electrical process.
"Listen!" Ellen said suddenly.
Sam strained his ears. At first he could detect nothing at all. Then he noticed a dim, lonely humming, that seemed to emanate from the ground, and from the bricks of the laboratory.
The sound seemed to be getting gradually louder. It made Sam shudder with the mystery of hidden things. And he began to feel, too, a sharp ache in his muscles, quite distinct from the soreness of his minor injury.
Suspicion grew on him again; suspicion that his latest experiment had been not entirely without lasting effect. Something had happened! Something had been started after all!