rom his pocket. The X-plosive shell completely
volatilized the stranger and hurled the party backward toward the
Skylark, into which they fled hastily. As Crane, the last one to enter
the vessel, fired his pistol and closed the massive door, Seaton leaped
to the levers. As he did so, he saw a creature materialize in the air of
the vessel and fall to the floor with a crash as he threw on the power.
It was a frightful thing, like nothing ever before seen upon any world;
with great teeth, long, sharp claws, and an automatic pistol clutched
firmly in a human hand. Forced flat by the terrific acceleration of the
vessel, it was unable to lift either itself or the weapon, and lay
helpless.

"We take one trick, anyway!" blazed Seaton, as he threw on the power of
the attractor and diffused its force into a screen over the party, so
that the enemy could not materialize in the air above them and crush
them by mere weight. "As pure mental force, you're entirely out of my
class, but when you come down to matter, which I can understand, I'll
give you a run for your money until my angles catch fire."

"That is a childish defiance. It speaks well for your courage, but ill
for your intelligence," the animal said, and vanished.

A moment later Seaton's hair almost stood on end as he saw an automatic
pistol appear upon the board directly in front of him, clamped to it by
bands of steel. Paralyzed by this unlooked-for demonstration of the
mastery of mind over matter, unable to move a muscle, he lay helpless,
staring at the engine of death in front of him. Although the whole
proceeding occupied only a fraction of a second, it seemed to Seaton as
though he watched the weapon for hours. As the sleeve drew back, cocking
the pistol and throwing a cartridge into the chamber, the trigger moved,
and the hammer descended to speed on its way the bullet which was to
blot out his life. There was a sharp click as the hammer fell--Seaton
was surprised to find himself still alive until a voice spoke,
apparently from the muzzle of the pistol, with the harsh sound of a
metallic diaphragm.

"I was almost certain that it wouldn't explode," the stranger said,
chattily. "You see, I haven't derived that formula yet, so I couldn't
make a real explosive. I could of course, materialize beside you, under
your protective screen, and crush you in a vise. I could materialize as
a man of metal, able to stand up under this acceleration, and do you to
death. I could