et you. Remember? I commented on the fact that
there must be life throughout the Universe, much of it that we could not
understand; and you replied that there would be no reason to suppose
them awful because incomprehensible. That may be the case here."

"Well, I'm going to find out," declared Seaton, as he appeared with a
box full of coils, tubes, and other apparatus.

"How?" asked Dorothy, curiously.

"Fix me up a detector and follow up one of those beams. Find its
frequency and direction, first, you know, then pick it up outside and
follow it to where it's going. It'll go through anything, of course, but
I can trap off enough of it to follow it, even if it's tight enough to
choke itself," said Seaton.

"That's one thing I got from that brain record."

* * * * *

He worked deftly and rapidly, and soon was rewarded by a flaring crimson
color in his detector when it was located in one certain position in
front of one of the meters. Noting the bearing on the great circles, he
then moved the _Skylark_ along that exact line, over the reflectors, and
out beyond the island, where he allowed the vessel to settle directly
downwards.

"Now folks, if I've done this just right, we'll get a red flash
directly."

As he spoke the detector again burst into crimson light, and he set the
bar into the line and applied a little power, keeping the light at its
reddest while the other three looked on in fascinated interest.

"This beam is on something that's moving, Mart--can't take my eyes off
it for a second or I'll lose it entirely. See where we're going, will
you?"

"We are about to strike the water," replied Crane quietly.

"The water!" exclaimed Margaret.

"Fair enough--why not?"

"Oh, that's right--I forgot that the _Skylark_ is as good a submarine as
she is an airship."

Crane pointed number six visiplate directly into the line of flight and
started into the dark water.

"Mow deep are we, Mart?" asked Seaton after a time.

"Only about a hundred feet, and we do not seem to be getting any
deeper."

"That's good. Afraid this beam might be going to a station on the other
side of the planet--through the ground. If so, we'd have had to go back
and trace another. We can follow it any distance under water, but not
through rock. Need a light?"

"Not unless we go deeper."

For two hours Seaton held the detector upon that tight beam of energy,
traveling at a hundred miles an hour, the h