Larry, watching tensely, saw a curious, bird-like something fluttering about in the red ray, _swiftly growing larger_!

Deliberately, and pausing to aim carefully for each shot, the girl emptied the little gun at the figure. Her body was rigid, her small face was firmly set, though she was breathing very fast.

A curious numbness had come over Larry. His only physical sensations were the quick hammering of his heart, and a parching dryness in his throat. Terror stiffened him. Though he would not have admitted it, he was paralyzed with fear.

The glittering thing that fluttered about in the crimson ray was not an easy target. When the gun was empty, it seemed still unharmed. And its wings had increased to a span of a foot.

"Too late!" Agnes gasped. "Why didn't we do _something_?"

Trembling, horror-stricken, she shrank toward Larry.

He was staring at the thing in the pillar of scarlet light.

It had dropped to the crystal disk upon which the red ray fell from the huge, glowing tube above. It stood there, motionless except for the swift increase of its size.

Larry gazed at it, lost in fear and wonder. It was like nothing he had ever seen. What was it that Agnes had said, of machine-monsters, of human brains in mechanical bodies? His brain reeled. He strained his eyes to distinguish the monstrosity more clearly. It was veiled in crimson flame; he could not see it distinctly.

But suddenly, when it was as tall as himself, it sprang out into the room, toward Larry and the shuddering girl. Just off the crystal disk, beyond the scarlet pillar of fire, it paused for long seconds, seeming to regard them with malevolent eyes.

For the first time, Larry could see it plainly.

Its body, or its central part, was a tube of transparent crystal; an upright cylinder, rounded at upper and lower ends. It was nearly a foot in diameter, and four feet long. It seemed filled with a luminous, purple liquid.

About the cylinder were three bands of greenish, glistening metal.

Attached to the lower band were four jointed legs of the same bright green metal, upon which the strange thing stood.

Set in the middle band were two glittering, polished lenses, which seemed to serve as eyes, and Larry felt that they were gazing at him with malevolent menace. Behind the eyes, two wings sprang from the green band. Ingenious, folding wings, of thin plates and bars of green metal.

And from the upper band sprang four slender, glistening, whip-like tentacles, metallic and brilliantly green, two yards in length. They writhed with strange life!

It seemed a long time to Larry that the thing stood, motionless, seeming to stare evilly at them with eye-like lenses. Then, lurching forward a little, it moved toward them upon legs of green metal. And now Larry saw another amazing thing about it.

Floating in the brilliant violet liquid that filled the crystal tube was a gray ma.s.s, wrinkled and corrugated. This was divided by deep clefts into right and left hemispheres, which, in turn were separated into larger upper and smaller lower segments. White filaments ran through the violet liquid from its base toward the three rings or bands of green metal that encircled the cylinder.

In an instant, Larry realized that the gray ma.s.s was a human brain.

The larger, upper part the cerebrum, the smaller ma.s.s at the back the cerebellum. And the white filaments were nerves, by means of which this brain controlled its astounding, mechanical body!

A brain in a machine!

The violet liquid, it came to Larry in his trance of wonder, must take the place of blood, feeding the brain-cells, absorbing waste.

An eternal mind, within a machine! Free from the ills and weaknesses of the body. And devoid, too, of any pity, of any tender feelings. A cold and selfish mind, without emotion--unless it might worship itself or its mechanical body.

It was this monster that had spilt the pool of blood drying on the floor, near the door. And it was these glistening, green, snake-like tentacles that had crumpled the revolver into a broken ma.s.s of steel!

Abruptly the machine-monster darted forward, running swiftly upon its four legs of green metal. Slender tentacles reached out toward the shuddering girl at Larry's shoulder.

"Run!" Agnes gasped to him, quickly. "It will kill you!"

The girl tried to push him back.

As she touched him, Larry recovered from his daze of wondering fear.

Agnes was in frightful danger, and facing it with quiet courage. He must find a weapon!

Wildly, he looked about him. His eyes fell upon the tall, heavy wooden stool, upon which Agnes had been sitting.

"Get back!" he shouted to her.

He s.n.a.t.c.hed up the stool, and, swinging it over his head, sprang toward the machine of violet-filled crystal and glittering green metal.

"Stop!" Agnes screamed, in a terrified voice. "You can't--"

She had run before him. He seized her arm and swung her back behind him. Then he advanced warily toward the machine-monster, which had paused and seemed to be regarding him with sinister intentness, through its glistening crystal eye-lenses.

With all his strength, Larry struck at the crystal cylinder, swinging the stool like an ax. A slender, metallic green tentacle whipped out, tore the stool from his hands, and sent it crashing across the room, to splinter into fragments on the opposite wall.

Larry, sent off his balance, staggered toward the glittering machine.

As he stumbled against the transparent tube that contained the brain, he clenched his fist to strike futilely at it.

A snake-like metal tentacle wrapped itself about him; he was hurled to the floor, to sprawl grotesquely among broken apparatus.

His head came against the leg of a bench. For a few moments he was dazed. But it seemed only a few seconds to him before he had staggered to his feet, rubbing his bruised head. Anxiously, he peered about the room.

The machine-monster and Agnes were gone!

He stumbled back to the ma.s.s of apparatus in the center of the huge laboratory. Intently, he gazed into the upright pillar of crimson flame. Nothing was visible there.

"No, the other!" he gasped. "The violet is the way they went."

He turned to the companion ray of violet radiance that beat straight down on the opposite side of the tiny, whirling planet. And in that motionless torrent of chill violet flame he saw them.

Tiny, already, and swiftly dwindling!

With green wings outspread, the machine-monster was beating swiftly upward through the pillar of purple-blue flame. And close against the crystal tube that contained its brain, was Agnes, held fast by the whip-like tentacles of glistening green metal.

Larry moved to spring after them, into the torrent of violet light.

But sudden caution restrained him.

"I'd shrink, too!" he muttered. "And then where would I be? I'd be standing on the gla.s.s platform, I guess. And the thing flying off over my head!"

He gazed at the rapidly dwindling forms of Agnes Sterling and her amazing abductor. As it grew smaller, the machine-monster flew higher in the violet beam, until it was opposite the tiny, spinning planet.