like distant ice, and his lips smiled.
“I prayed,” he said softly. “I was answered. You, new man! Get down on your belly.”
Loris grinned at Birek, but there was no humor in his eyes. He had drawn a little away from MacVickers. He said carelessly:
“There’s no time for that now, Birek. It’s our shift. They’ll be burning us if we don’t go.”
Birek repeated, “Down on your belly,” not looking at Loris.
A vein began to throb on MacVickers’ forehead. He looked slight, almost small against the Venusian’s huge bulk.
He said quietly, “I’m not looking for trouble.
“Then get down.”
“Sorry,” said MacVickers. “Not today.”
Pendleton’s voice cracked out sharply. “Let him alone, Birek! You men, down the ladder! They’re going for the shockers.”
MacVickers was aware of movement overhead, beyond the glass roof. Men began to drop slowly, reluctantly, down the ladder. There was sweat on Pendleton’s forehead and Loris’ face was as grey as his eyes.
Birek said hoarsely, “Down! Grovel! Then you can go.”
“No.” The ladder was beyond Birek. There was no way past him.
Loris said, in a swift harsh whisper, “Get down, MacVickers. For God’s sake get down, and then come on!”
MacVickers shook his head stubbornly. The giant smiled. There was something horribly wrong about that smile. It was the smile of a man in agony when he feels the anaesthetic taking hold. Peaceful, and happy.
He struck out, startlingly fast for such a big man. MacVickers shrank aside. The fist grazed past his head, tearing his ear. He crouched and went in, trying for a fast body-blow and a sidestep.
He’d forgotten the glimmering sheathe. His fist struck Birek on the mark, and it was like striking glass that didn’t shatter. The pain shot up his arm, numbing, slowing, sickening. Blood spattered out from his knuckles.
Birek’s right swept in, across the side of his head.
MacVickers went down, on his right side. Birek put a foot in the small of his back. “Down,” he said. “Grovel.”
MacVickers twisted under the foot, snarling. He brought up his own feet, viciously, with all his strength. The pain of impact made him whimper, but Birek staggered back, thrown off balance.
There was no sign of hurt in his face. He stood there, looking down at MacVickers. Suddenly, shockingly, he was crying. He made no sound. He didn’t move. But the tears ran out of his eyes.
A deep, slow shudder shook MacVickers. He said softly, “There’s no pain, is there?”
Birek didn’t speak. The tears glistened over the faint, hard film on his cheeks. MacVickers got up slowly. The furrows were deep and harsh in his face and his lips were white.
Loris pulled at him. Somewhere Pendleton’s voice was yelling, “Hurry! Hurry, please !”
*
The guards were doing something overhead. There was a faint crackling sound, a flicker of sparks in a circle around the top of the wall. Shivering, tingling pain swept through MacVickers from the silver collar at his throat.
Men began to whisper and curse. Loris clawed at him, shoved him down the ladder, kicked his face to make him hurry. The pain abated.
MacVickers looked up. The great corded legs of Birek were coming down, the soles of the feet making a faint, hard sound on the rungs.
The hatch closed overhead. The voice of the dying Earthman came dry and soft over his shoulder.
“Here’s where you’ll work until you die. How do you like it?”
MacVickers turned, scowling. It was hot. The room above was cool by comparison. The air was thick and sluggish with the reek of heated oil and metal. It was a big space, running clear to the curving wall, but the effect was of stifling, cramped confinement.
Machinery crammed the place, roaring and hissing and clattering, running in a circuit from huge intake pumps through meaningless bulking shapes to a forced-air outlet, with oil-pumps between them.
The pumps brought mud into a broad sluice, and the blue-green stain of it was everywhere.
There were two glassite control boxes high on the walls, each with a black, tentacled Europan. About five feet overhead was a system of metal catwalks giving complete coverage of the floor area. There were Europans on the walks, too, eight of them, patrolling steadily.
Their sleek, featureless bodies were safe from contact with the mud. They carried heavy plastic tubes in their tentacles, and there were heavy-duty shockers mounted at every intersection.
MacVickers grinned dourly. “Trustful lot.”
“Very.” Pendleton nudged him over toward a drive motor attached to some kind of a centrifugal separator. Loris and the blue-sheathed Earthman followed, with Birek coming slowly behind him.
MacVickers said, “What’s all this for?”
Pendleton shook his head. “We don’t know. But we have an idea that Jovium comes from the mud.”
“Jovium!” MacVickers’ grey-green eyes began to grow hot. “The stuff that’s winning this war for them. The metal destroyer!”
“We’re not sure, of course.” Pendleton’s infinitely weary eyes turned across the stretch of greasy metal deck to the end of the circuit. “But look there. What does that suggest to you?”
The huge pipe of the forced-air ejector ran along the deck there behind a screen of heavy metal mesh. Just above it, enclosed behind three thicknesses of glassite, was a duct leading upward. The duct, from the inordinate size of its supports and its color, was pure lead.
Lead. Lead pipe, lead armor. Radiations that changed living men into half-living diamonds. Nobody knew what Jovium was or where it came from—only it did.
But scientists on the three besieged worlds thought it was probably an isotope of some powerful radioactive metal, perhaps uranium, capable of setting up a violent progressive breakdown in metallic atoms.
“If,” said MacVickers softly, “the pipe were lined with plastic....Blue mud! I’ve traded through these moons, and the only other deposit of that mud is a saucepanful on J-XI! This must be their only source.”
Loris shoved an oil can at him. “What difference does it make?” he said savagely.
MacVickers took the can without seeing it. “They store it up there, then, in the space between the inner wall and the outer. If somebody could get up there and set the stuff off....”
Pendleton’s mouth twisted. “Can you see any way?”
He looked. Guards and shockers, charged ladders and metal screens. No weapons, no place to conceal them anyway. He said doggedly:
“But if someone could escape and get word back....This contraption is a potential bomb big enough to blow Io out of space! The experts think it only takes a fraction of a gram of the pure stuff to power a disintegrator shell.”
There was a pulse beating hard under his jaw and his grey-green eyes were bright.
Loris said, “Escape.” He said it as though it were the most infinitely beautiful word in existence, and as though it burned his mouth.
“Escape,” whispered the man with the shimmering, deadly sheathe of aquamarine. “There is no escape but—this.”
*
MacVickers said, into the silence that followed, “I’m going to try. One thing or the other, I’m going to try.”
Pendleton’s incredibly tired eyes looked