figure one of his hands reached up and openedhis skull as one opens the hinged halves of a box. From within the skullthere rolled a great shining slug, a sinisterly beautiful figure ofglowing opalescence, with a scarlet nucleus! For one breath-takeninstant it rose to its full height of four feet, hesitated, as if warilyregarding the horror-struck men, then with tendrils pressed into itsbody until it was nearly spherical, the slug that had been Layroh rolledlike a ball of living fire across the cavern toward the cluster ofmachines. Foster snatched up one of the discarded pistols from the floorand fired twice at that hurtling globe of flame, but both shots missed.
A moment later the slug reached the machines. It fled swiftly past agroup of smaller mechanisms and selected a gleaming metal colossus whosesize and formidable armament indicated that it was designed primarily asan instrument of war. With whipping tendrils the slug swarmed up one ofthe metal legs and into a small crystal-walled compartment in theforward end of the machine.
There was the crackling hiss of unleashed sub-atomic forces somewherewithin the metal body. The machine moved in fumbling uncertainty for amoment as the slug fought to get control of mechanism that had lain idlefor a thousand centuries! Then swiftly full control came, and themachine came charging toward the men.
They broke in wild panic before the onslaught of the metal monster. Asan engine of war it was invincible. Six feet in height and nearly twentyfeet in length, it maneuvered upon its jointed legs with bewilderingspeed and efficiency. A score of rodlike arms projected from the maintrunk, arms that were equipped for nearly every purpose. Some ended inpincers, others in barbed points, and others in clusters of flexiblemetal tentacles.
One of the men screamed in terror and broke for the door back into thepit 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 isto stick together and fight it out."
* * * * *
It was a chance that seemed increasingly slight as they tried to closein upon the machine. Garrigan had recovered the other pistol from thefloor. He emptied it into the metal monster at a range of less than tenfeet but the bullets glanced harmlessly off as from armor plate.
The machine fought back with deadly efficiency. One of thedagger-pointed arms impaled a man like a speared fish. Pincers closedupon the neck of another, half tearing his head from his body. With thestrength of desperation the men wrecked the pillars-and-diaphragmapparatus 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 achance to use them against some vulnerable spot in the machine, but hesaw none. There was a bare chance that if he could gain the machine'sback he might find some crevice through which he could send a tellingshot. Cramming the pistol into his belt, he watched his chance, thenused the debris of the wrecked apparatus as a stepping stone for arunning leap that landed him solidly on top of the metal bulk just backof the crystal compartment.
He fumbled for the pistol in his belt, but before he could even touch ita tentacle-tipped arm lashed down toward him, picked him off the thing'sback, and flung him with terrific force high into the air....
* * * * *
For a breathless moment he saw the girders and cables of the ceilinghurtling toward him. Instinctively he grabbed with both hands at one ofthe lower girders as his body thudded into it. His clutching fingersslipped momentarily, then held, leaving him dangling there at arms'length thirty feet above the floor.
His wits swiftly clearing from the shock of that mighty toss throughspace, Foster scrambled up on the narrow girder. Sitting astride themetal beam, he looked down at the scene below.
The battle down there was nearly over. The glowing slug in the machinewas now obviously trying to capture the remaining men alive for furtheruse. Instead of slaying, its lashing arms fought only to stun andcripple.
Six of the men still remained on their feet but they were trapped in anangle between heavy apparatus and one of the walls. In the central casethe ten semi-dormant slugs, still too inactive to take part in thebattle themselves, seemed watching the conflict with great unwinkingeyes of crimson.
Foster groaned. The metal colossus was too powerful for their feebleefforts. It would take a bolt of lightning to have any effect upon thatmighty engine of war. At the thought, Foster's heart leaped in suddeninspiration. There was lightning, the terrific electrical force of aspinning planet, in the cables up here among the girders, if he couldonly release it.
* * * * *
Slightly below his position and barely six feet away from him one of themain power cables of the cavern was suspended from heavy insulators. Ifthe cable had ever had an insulating sheath around it the fabric hadvanished during the centuries for the dull silver-colored metal was nowcompletely bare.
If that naked cable could be dropped into contact with Layroh'smachine-body, the entire power of one of the cavern's main lines wouldbe grounded through the metal of the machine. The position of the cablewith regard to where the machine was now, was perfect for the scheme. IfFoster could sever the cable just opposite him there was an excellentchance that the longer one of the free ends would drop directly uponthe machine.
And in his possession he had a possible means of severing thatcable--the pistol that was still crammed in his belt. There were fourshots remaining in the pistol. The cable was barely half an inch thick,but the range was so short that he could not very well miss. If thesilver-colored metal was as soft as it looked, the heavy bullets shouldbe enough to tear through it.
Foster thrust the pistol as close to the cable as he could reach. Then,with the muzzle scarcely a yard from the silver strand, he fired. Theheavy bullet caromed from the cable's surface, but not before it hadtorn a gash nearly a third of the way through it.
There was a sudden cessation of activity below as the slug in themachine looked up at the sound of the shot. Swift inspiration seizedFoster and he promptly sent his next shot down at the machine itself.The bullet glanced harmlessly off, but his ruse worked. Apparentlybelieving that Foster was merely trying another futile attack upon it,the machine turned its attention back to the men it had cornered. Fostercould be attended to later.
* * * * *
Foster slipped and nearly fell just as he fired at the power line thenext time and his shot missed. That left him only one remainingcartridge. Aiming with infinite care he sent his last shot smashingsquarely into the part of the cable remaining intact.
It trembled and sagged as the bullet cut the remaining metal nearlythrough. Only a bare thread was left, yet that thread held. Sick atheart over the narrow margin by which his effort had failed, Fosterstared in despair at the nearly severed cable. It needed only one solidblow to tear that last thread of metal apart, but the cable was justfar enough away to be effectively beyond his reach.
Then suddenly Foster's eyes narrowed. There was a way remaining by whichthe weakened power line could be broken. A single hurtling dive out anddownward from the girder would send his own body crashing squarely intothe metal strand. Beneath the smashing impact of his one hundred andeighty pounds the nearly severed cable was certain to break.
Foster shuddered as he realized what that dive into space would mean. Hewas not thinking of the fall itself. The thirty-foot drop to thediamond-hard floor of the cavern would in all probability mean death orbroken bones, but that was a hazard which Foster was willing to take.
It was the thought of what would happen in the brief moment of contactwhen his body met that bare cable that drained the color from Foster'sface. There was the terrific electrical energy from a spinning worldcoursing through that silver strand, a force that in all probability waspowerful enough to instantly char a human body to a glowing cinder!
*
* * * *
If he could only insulate his body at the point where it would touch thecable he might have at least a chance of surviving the contact. The onlypossible insulating medium he had was the clothing he wore--a pair ofheavy corduroy trousers and the sleeveless remnant of a woolen shirt.They could be rolled into a bundle that would be bulky enough to atleast give him some protection from contact with the bare cable.
Laying the empty pistol on the girder beside him, he stripped as quicklyas his precarious perch would permit. Then, using the pistol as acentral core to give body to the bundle, he swathed it deep within thefolds of the clothing, making a thick roll that he could hold in hisright hand as he leaped.
At best the insulating qualities of the roll would be far from perfect,yet it might serve to minimize the effects of the cable's charge enoughto give him some chance of escaping alive. His contact with the powerline would be only for the fractional part of a second and his bodywould be completely in the air at