gun from its shoulder strap and his right closing on the astonished Oriental's wind-pipe. It was the work of only an instant to choke him in unconsciousness and lock him in the sealed cell.

"Quick, the chute!" hissed Fuller. He dived head foremost into a rectangular wooden trough that was used for the disposal of the gangue from a crushing mill above. This chute, Fuller had said, led to the outside at the back of the reduction plant.

Across the passage Luke saw a squad of convicts and two guards emerging from the lift. Then he plunged down the steeply inclined trough after Fuller. As he slid and tumbled into the darkness, he heard the hoarse shouting of the guards.

He landed heavily in the pile of gangue at the base of the chute; then was scrambling and slipping down with an avalanche of the sharp edged stone. At the bottom, he saw that Fuller had already started up the slope of the great pit which enclosed the Workshop. Luke darted after him.

They were hidden from the bastion by the buildings of the smelter and reduction plant. But the loud yelling of guards back there in the pit gave evidence that word of the escape was being passed along to Gannett. Before they were halfway up the slope there was the shriek of the alarm siren, and Luke felt his body sag with a sudden increase of weight. Fool that he had been to trust the scrawny scientist!

"It's the broadcast," panted Fuller, beside him. There is some effect, of course. You're probably carrying fifty extra pounds."

"Huh!" Luke hoped it would be no worse.

Fuller slipped into a narrow crevasse that ran slantwise of the slope and extended upward to the rim of the pit. The going was much easier here and they made rapid progress toward the top. Suddenly Luke realized that it was growing very cold; there was a bite to the foul air, and moisture from the red mist was frosting his beard. The liberation of the tiny planet and consequent shifting of the terminator was bringing frigidity to Vulcan's Workshop.

They came up out of the crevasse at the top of the pit and Luke could not resist looking back. Every convict in sight was flattened to the ground. They sprawled singly and in heaps, each one a squashed inert thing that would not move again until the neutro-broadcast was discontinued. The guards, confident they would find the escaped prisoners in like condition, were searching the slope below them.

Luke raised Chan Dai's, dart gun to his shoulder.

Fuller struck aside the muzzle of the weapon. "No!" he protested, "No unnecessary killing, Fenton. They're completely fooled, and we'll be well on our way before they know the truth."

Grumbling, Luke drew back from the rim of the excavation.

Up here the ground was fairly level, but there were many fissures and small craters which made the footing precarious. The mists were so dense they could see scarcely two hundred feet ahead.

"We'll be lost in the vapors when they finally wake up and come out after us," Fuller said. "And look Fenton, off there to the left are the three columns of fire that mark the rendezvous."

They plunged on through the red mist toward the flaming pillars. Those beacons, even though they subsided at regular intervals, quickly reappeared after each cessation. And their brilliance penetrated the mists with ease at this distance of about two miles. There was no fear of missing their destination.

"Sure your friends'll be there?" Luke asked doubtingly. He was beginning to have some misgivings about the matter—the scientist had been anything but explicit as to who these friends were. And the longer his thoughts dwelt upon the things Fuller had told him the more suspicious he became. Pretty cagey about everything but the actual getting away from the Workshop, Fuller had been.

"Certainly they will; they've been waiting two days." Fuller's tone was impatient and his words came painfully. "You leave that part of it to me, Fenton," he gasped. There was a fleck of blood at his lips.

As the scientist stumbled on through the mists, Luke's doubts increased and he began to lose his respect for the man's intellect and for the cunning which had enabled him to outwit the neutralizing energies used by the guards. After all, he was a weak and puny specimen. They all were, the smart guys who held the people of two worlds in their power by exercising the knowledge they had learned from books. And this one had failed even in that; whatever he might have been, he had run afoul of the law himself and was already a doomed man. Tricks! This trick of Fuller's had gotten them away, but of what use was it without the brute force necessary to carry on to a successful end?

The brawn Tom had spoken of so slightingly was what they needed from this time on, and nothing else would save them. Luke had that brawn; Fuller did not. The scientist slipped and nearly lost his balance at the edge of a fissure, but Luke made no move to help him. It was every man for himself at this stage of the game.

Increasing difficulty came with every step. Now they were sliding and rolling into a deep crater, now scrambling up its steep sides with hands torn and bodies bruised by the jagged boulders. A yawning crevasse opened before them and they were forced to skirt its edge for fully a half mile in the wrong direction before they found a crossing. And the cold was unbelievably intense. Numbed and silent, with their eyes half blinded and lungs seared by the frosty air, they struggled on toward the three pillars of flame.

And still Tom Fuller carried on, though Luke was now in the lead.

They had covered probably half the distance to the flaming columns when shouts arose behind them. The guards were on their trail.

"Can't—find us," Fuller panted. "The mists——"

"Hell, the mists are clearing," Luke snarled. "You ain't so damn smart as you think."

What he said was true. Though there was less light on account of the new angle with the sun farther below the horizon, the red mist was definitely lighter in color, noticeably less dense. Visibility was good to several hundred yards. Luke turned his head, but could see nothing of their pursuers.

"They can't," Fuller insisted weakly.

Luke, pushed on with renewed vigor, ignoring him, cursing.

And then there came faintly to his ears the twang of a dart gun; the shrill scream of its deadly vibrating missile; a violent blow that flung him headlong.

Like a cat, he bounced to his feet, crouching with Chan Dai's dart gun at his shoulder. A strangely grotesque heap was at his feet—Tom Fuller. Off there in the thinning mist he saw a shadowy figure and he fired at it twice. Whether his darts found their mark he was never to know, for a wall of white swept down suddenly to obscure his vision. Snow! Great massed flakes falling endlessly—the moisture of the mist crystallized and closing in on him to hide him even more safely, than had the mists themselves.

He was on his knees then at Fuller's side. A brilliant flash and a screaming roar over amongst the rocks apprised him of the fact that the guard's dart had gone wide. And yet Fuller was down, moaning with pain. Luke tried to turn him over and found that his body had taken on tremendous weight. He was flattened, crushed to the rocky surface of Vulcan by the full force of its gravity!

"What the devil!" he grunted as he heaved and strained. "What'd they do to you, old man?"

With great effort he succeeded in turning the scientist face up. Then he saw what had happened, and knew in a flash that Fuller had saved him from the singing dart whose energy was making a sizzling puddle of the stones where it had landed. The missile, in passing, had carried away the belt and part of the fabric of Tom's garment—carried away the capsule and the radium