cited, but
he was curious too.

"Come with me, my boy. I'll show you." The old man led him from the room
and the others followed respectfully.

* * * * *

They stopped at a circular port and Karl saw that they were high above
the earth in a vessel that hovered motionless, quivering with what
seemed like human eagerness to be off.

"This vessel?" he asked.

"It's a huge sphere; the base of our operations. To it we drew the aero
on which you were fighting. A magnetic force discovered by our
scientists and differing only slightly from that used in counteracting
gravity. We let the rest of them go; foolishly I think. But it's done
now and we have no fear. From this larger vessel we shall send forth
smaller ones, armed with the heat-ray. The flagship of the fleet is to
be yours and you'll lead the attack on Dorn. Here--I'll show you the
Zar."

They had reached the room of the detectoscopes--a mass of mechanisms
that reminded Karl of nothing so much as the vitals of the intermediate
levels which he had visited with Leon--and Rhoda. He knew that he
flushed when he thought of her. What a fool he had been!

A disc glowed as one of the silver-robed strangers manipulated the
controls. The upper surface of Dorn swung into view. Rapidly the image
drew nearer and they were looking at the crystal pyramid that was the
Zar's palace. Down, down to its very tip they passed. Karl recoiled from
the image as it seemed they were falling to its glistening sides. The
sensation passed. They were through, penetrating solid crystal, masonry,
steel and duralumin girders. Room after room was opened to their view.
It was magic--the magic of the upper levels.

* * * * *

Now they were in the throne room. A group of purple-clad men and women
stood before the dais. Leon, Rhoda--all of his wild companions were
there, facing the dais. The Zar was raging and the words of his speech
came raucously to their ears through the sound-producing mechanism.

"You've failed miserably, all of you," he screamed. "He's gotten away
and you know the penalty. Taru--the vibrating ray!"

The Moon man already was fussing with a gleaming machine, a machine with
bristling appendages having metallic spheres on their ends, a machine in
which dozens of vacuum tubes glowed suddenly.

Rhoda screamed. It was a familiar sound to Karl. He noted with
satisfaction that Leon could hardly stand on his feet and th