selected a gleaming metal colossus whose
size and formidable armament indicated that it was designed primarily as
an instrument of war. With whipping tendrils the slug swarmed up one of
the metal legs and into a small crystal-walled compartment in the
forward end of the machine.

There was the crackling hiss of unleashed sub-atomic forces somewhere
within the metal body. The machine moved in fumbling uncertainty for a
moment as the slug fought to get control of mechanism that had lain idle
for a thousand centuries! Then swiftly full control came, and the
machine came charging toward the men.

They broke in wild panic before the onslaught of the metal monster. As
an engine of war it was invincible. Six feet in height and nearly twenty
feet in length, it maneuvered upon its jointed legs with bewildering
speed and efficiency. A score of rodlike arms projected from the main
trunk, arms that were equipped for nearly every purpose. Some ended in
pincers, others in barbed points, and others in clusters of flexible
metal tentacles.

One of the men screamed in terror and broke for the door back into the
pit room. Foster flung him aside and slammed the door shut and locked.

"You'd be trapped like a rat in there," he grated. "Our only chance is
to stick together and fight it out."

* * * * *

It was a chance that seemed increasingly slight as they tried to close
in upon the machine. Garrigan had recovered the other pistol from the
floor. He emptied it into the metal monster at a range of less than ten
feet but the bullets glanced harmlessly off as from armor plate.

The machine fought back with deadly efficiency. One of the
dagger-pointed arms impaled a man like a speared fish. Pincers closed
upon the neck of another, half tearing his head from his body. With the
strength of desperation the men wrecked the pillars-and-diaphragm
apparatus and from the debris tore metal fragments to serve as clubs.
Their blows against the thing's pistonlike legs failed to even shake it.
Two more men died before the grim efficiency of the stabbing arms.

Foster had held the remaining bullets in his own pistol, waiting for a
chance to use them against some vulnerable spot in the machine, but he
saw none. There was a bare chance that if he could gain the machine's
back he might find some crevice through which he could send a telling
shot. Cramming the pistol into his belt, he watched his chance, then
used the d