food. The night reechoed with the harsh cacophony of their cries.

  With lumbering caution, its smooth knob head waving on a longreptilian neck, its heavy armored tail dragging behind its body'sfolds of flesh, a giant night-thing came stumping out of a copse ofjungle growth--a buru. Its eyes were watchful, but centered mainly onthe pool of water to one side of the peninsula of firm soil. Itsdrinking water was there. With several pauses, it went right out onthe spit, and a flat-bottomed foot twice the size of an elephant'smissed one of the sleeping forms by inches. But the buru cared not forthem. It was not a flesh-eater. Its undulating neck stretched far out;its head dipped; water was lapped up--until it caught sight of theuprooted giant stump lying pitched in the pool. The beast drank butlittle after that, and retreated as cautiously as it had come.

  Five or six of its fellows of the swamps followed at intervals to thewater, grotesque hulking shapes, odorous and slimy with mud. All drankfrom the same spot; all ignored, save for a tentative rooting snuffle,the unconscious figures lying puny beneath them. But all noticed thetwisted roots of the stump, sticking out in a score of directions, andavoided them.

  And then there came smaller, more cautious animals who did not drinkfrom the favored spot, who surveyed it, sniffed, hesitated, andfinally retreated. There was a good reason for this caution.

  For with the falling of night the stump had been at least thirty feetout in the water; now it was not ten feet from the side of the spit,and not twelve feet from the nearest sleeping figure. The suits thatclad the three figures were sealed, the face-plates closed, so therewas probably--after their trip through the void--no man smell toattract the giants of swamp and trees. But those three figures hadmoved. That was lure enough for one monster.

  When the first ruddy arrows of Jupiter's light laced through thejungle's highest foliage, the twisted, gnarled stump was settled onthe peninsula's rim, half out of the water. And when day burst, whenJupiter's flaming arch pushed over into view, the long seeming-rootseeled forward in sinuous reptilian life.

  * * * * *

  In one second Hawk Carse was snatched from sleep into the turmoil of afight for life.

  Something hard and enormously powerful was wrapping his waist with avise-like grip that threatened to cut him in two. He felt a leg go upand crumple back, almost breaking under the force of a lashing blow.He was squeezed in, caged, compressed, by a score of tough, encirclingtentacles, and his whole body was drawn toward a wide, flexible,black-lipped mouth yawning in the center of the monster he had thoughta stump. Moving with loathsome life, its sinewy root-tentacles suckinghim whole into the maw, the thing hunched itself back to the water.

  The water frothed around Carse. He had been too dazed to resist; hehad not known what had gripped him in his unconsciousness andweakness. But he remembered his ray-gun.

  The lips of the hideous mouth were pressing close. Both were now underthe surface. Carse's suit was still tight and he could breathe evenwhile totally submerged in the water. He strained his left arm againstthe tentacle that looped it, worked the ray-gun still clasped in hishand in line with the thing's monstrous carcass, and at once, gaspingand sick, pulled the trigger clear back.

  The orange stream sizzled as it cleared a path through the water andbit true into the gaping mouth. There sounded a curious, subterraneansob; beady eyes on each side of the mouth bulged; the woodish bodyquivered in agony. Its tentacles slackened, and, half fainting, theHawk wrenched free. He staggered up onto the land, streams of waterrunning off the suit, and toppled over; and from there he saw thething drag its writhing shuddering shape farther out from the shore.When perhaps sixty feet away it again subsided into a "harmless"uprooted old stump....

  * * * * *

  Carse lay resting and collecting himself for a quarter of an hour,while Leithgow and Friday slept on, unconscious of what had happened;then he got to his feet, opened their face-plates and bathedLeithgow's pale brow with water. The scientist awoke with thequickness of old men, but Friday stirred and stretched and blinked andsat up at last, yawning.

  The Hawk answered their questions about his wet suit with a briefexplanation of the fight, then got down to business.

  "There's water here, but we must have food," he said. "Friday, you goback and find fruit; some isuan weed, too, if it's growing nearby. Achew of it will stimulate us. Keep your ray-gun ready. I wouldn't behere if I'd not had mine."

  The isuan was a big help. In its prepared form it is degrading,mind-destroying, but in natural state it gives a powerful andcomparatively harmless stimulation. Chewing on the leaves that theNegro brought back, they made strength and renewed vitality for theirbodies, and came, for the first time since they had started theirflight through space, to a near-normal state. Meaty, yellow globulesof pear-like fruit, followed by prudent drafts of water, aided also.Friday's long-absent grin returned as he bit into the juicy fruit, andhe announced through a mouthful:

  "Well, things're lookin' sunny again! We've got food and water insideus; we can reach Master Leithgow's laboratory in these here suits; an'to top it all we've finished high an' mighty Ku Sui. He's dead atlast! Boy, it sure feels good to know it!"

  Eliot Leithgow was lying back, breathing deeply of the fresh morningair. His lined, worn face and body were relaxed. "Yes," he murmured,"it is good to know that Dr. Ku is now just a thing of the past. Heand his coordinated brains." He glanced aside at the Hawk, sittingsilent and still, and stroking, as always when in meditation, thebangs of flaxen hair which obscured his forehead. "Why so serious,Carse?" he asked.

  * * * * *

  The adventurer's gray eyes were cold and sober. No relaxation showedin them. His hand paused in its slow smoothing movement and he spoke.

  "Why I overlooked it before," he said quietly, almost as if tohimself, "I don't know. Probably because I was too tired, and toobusy, and too sick to think. But now I see."

  "What?" Leithgow sat up straight.

  "Eliot," said the Hawk clearly, "doesn't it seem strange to you thatKu Sui's asteroid continued to be invisible after we had smashedthrough its dome?"

  "What do you mean?"

  "We've assumed that our smashing the dome and opening it to spacekilled Ku Sui and everyone inside, and destroyed all the mechanisms,including the coordinated brains. But the mechanism controlling theasteroid's invisibility was not destroyed. The place remainedinvisible."

  The old scientist's face grew tense. Carse paused for a moment.

  "That means," he went on, "that Ku Sui provided the invisibilitymachine with special protection for just such an emergency. And do youthink he would give it such protection and not his coordinated brains?Wouldn't he first protect the brains, his most cherished possession?"

  Eliot Leithgow knew what this meant. The Hawk had promised the brainsin that machine--brains of five renowned scientists, kept cruelly,unnaturally alive by Dr. Ku--that he would destroy them. And hispromises were always kept.

  There was no evading the logic of this reasoning. The Master Scientistnodded. "Yes," he answered. "He certainly would."

  "I couldn't damage the case they were in," Carse continued. "The wholedevice seemed self-contained. It means just one thing: specialprotection. Since the mechanism for invisibility survived the crashingof the dome, we may be sure that the brain machine did too. And morethan that: we may assume that there was special protection for themost precious thing of all to Dr. Ku Sui--his own life."

  Friday's mouth gaped open. The old scientist cried out:

  "My God! Ku Sui--still alive?"

  "It would seem so," said Hawk Carse.

  He amplified his evidence. "Look at these space-suits we're wearing.We got them and escaped by them, but they're Dr. Ku's. Couldn't hehave protected himself with one too? He had plenty of time. And thenthe construction of the asteroid's buildings--all metal, with tight,sealed doors! Oh, stupid, stupid! Why didn't I see it all before?Here, in my weakness and sickness, I thought we'd killed Ku Sui
anddestroyed the coordinated brains!"

  Leithgow looked suddenly very old and tired. The calamity did not endthere. There were other angles, and an immediate one of high danger.In a lifeless voice he said:

  "Carse, our whole situation's changed by this. We intended to gostraight to my laboratory, but we may not be able to. The laboratorymay already be closed to us. And even if not, there'd be a big risk ingoing there."

  "Closed to us by what?" the Hawk demanded sharply. "At risk fromwhat?"

  Old Leithgow pressed his hands over his face. "Let me think a moment,"he said.

  * * * * *

  There were very good reasons why Eliot