f so vast a mass for more than moments. Huge masses rained to earth, to
bury themselves in the soil.

There came a momentary lull. Then suddenly, from the mass which
evidently held the wrecked engine room, there shot out a beam of intense
white light that swept around in a wide, erratic arc. Whatever it
touched fused instantly into a brilliantly glowing mass of liquid
incandescence. The field itself, fragments of the wreckage, fused and
mingled under its fury. The beam began to swing, faster and faster, as
the support that was holding it melted; then abruptly it turned upon
itself. There came a sudden blast of brilliance to rival that of the
sun--and the entire region became a molten lake. Eyes streaming,
temporarily blinded, the men turned away from the screen.

"That," said Arcot ruefully, "is that! It seems that our visitors don't
want to leave any of their secrets lying around for us to investigate.
I've an idea that all the other wrecks will go like this one did." He
scowled. "You know, we really didn't learn much. Guess we'd better call
the headquarters ship and ask for further instructions. Will you attend
to it, Lieutenant Greer?"

III

Swiftly Arcot's sleek cruiser sped toward New York and the Arcot
Laboratories. They had halted briefly at the headquarters ship of the
Earth-Venus forces to report on their experience; and alone again, the
three scientists were on their way home.

With their course set, Arcot spoke to the others. "Well, fellows, what
are your opinions on--what we've seen? Wade, you're a chemist--tell us
what you think of the explosion of the ship, and of the strange color of
our molecular ray in their air."

Wade shook his head doubtfully. "I've been trying to figure it out, and
I can't quite believe my results. Still, I can't see any other
explanation. That reddish glow looked like hydrogen ions in the air. The
atmosphere was certainly combustible when it met ours, which makes it
impossible for me to believe that their air contained any noticeable
amount of oxygen, for anything above twenty per cent oxygen and the rest
hydrogen would be violently explosive. Apparently the gas had to mix
liberally with our air to reach that proportion. That it didn't explode
when ionized, showed the absence of hydro-oxygen mixture.

"All the observed facts except one seem to point to an atmosphere
composed largely of hydrogen. That one--there are beings living in it! I
can understand how the Vener