Simms rested his paddle across the thwart and let the clumsy jagua drift. Ahead, where the indigo swamp growth thinned, an abuttment of white metal projected from the water, its near end forming a wafer-like conning tower.

Half-way Jetty at last! Two grueling weeks through Venus' Blue Mold Swamp were behind him. Even if he knew that this station marked the half way point to his final disgrace and humiliation, he could at least rest here, free from the incredible dangers of the marsh.

He swung the dugout to a landing, wearily stretched cramped legs and headed down the catwalk. Before him the door of the jetty opened and three men appeared in the entrance.

Earthmen!

"Halleck! Gately! Sterns!" Simms cried. "What the devil are you doing here?"

The taller of the men held the door open wider. "Come in, Simms," he said. "We've been expecting you."

Inside the spherical room the air was warm and dry. Simms unhooked his dehydration mask and surveyed the three quietly.

They weren't a lovely trio. Halleck was tall and swarthy with dark eyes and thin lips. He wore a stained rain-helmet and flexible swamp boots. Gately undoubtedly had Martian blood in his veins. And Sterns, a typical space-rat from the slums of Venus City, bore an old heat-gun scar across his face.

"I thought the Halleck Development Company was heading north," Simms said. "That's what you told the Commandante at Post One."

Halleck smiled. "We told your Commandante a lot of things that suited our purpose."

Simms stirred uneasily. "You also said you were geologists, looking for sedimentary deposits."

"Part of which is quite true." Halleck lit a cigarette deliberately, then nodded to Gately who drew from his pocket a small bag. The man jerked the draw string and permitted a dozen yellowish lumps to spill out on the table.

"Deleon Salts," Halleck said shortly.

Ice touched Simms' spine. He had of course seen these ochre crystals before, while on patrol duty in native Kamali villages. But in the possession of Earth men....

"Deleon Salts," Halleck said again, blowing a shaft of smoke ceilingward. "The stuff that holds the secret of rejuvenation for the Kamalis. We're going to get a lot of it, ship it back to Earth and sell it for a high price."

"But ... but good Lord, you can't do that...."

"I know what you're going to say," interrupted Halleck, "that although these salts enable the Kamalis to maintain eternal life, they mean instant death to a person of Earth. Well, we've taken care of that. We've worked out a process that makes them harmless for a year."

"And after that...?" Simms persisted.

Halleck shrugged. "After that we'll have made our pile. We're simply selling a drug guaranteed to erase the ravages of time. It'll go like wildfire."

Up on the wall a mercury clock pulsed rhythmically, and below the floor level sounded the faint drone of the dehydrators. Motionless, Simms sat there. Like wildfire, Halleck had said. And the words were only too true. The quest for perpetual youth was eternal. Earth men still envied the two hundred year old Martians, the three hundred year old Jovians. Tell them that these Deleon Salts were both harmless and effective, and the results would be cataclysmic.

Every person on Earth would demand some of the crystals. And in a year....

"Where did you get these salts?" Simms asked.

For answer Halleck reached forward and plucked something from the Venusian Service man's belt before the latter could restrain him. Capped and sealed at both ends, it was an official mold-proof message cylinder.

"Three weeks ago," Halleck said, tapping the cylinder with his finger, "you left Post One with this tube bound for Venusian headquarters at BeTaba. You were sent in person because any radio or visiscreen communication would of course be intercepted by the Kamali Oligarchs.

"The tube contains two messages. One asks for reinforcements at the Post because of a recent epidemic of Mold Fever. The other demands your resignation because of insubordination. Insubordination—refusing to obey orders. Right, isn't it?"

A knife of bitterness cut through Simms. Yes, it was right, every word of it.

He had come here to Venus direct from the Inner-Planet Military School on Earth. At Venus City he had waited six months before receiving his appointment to the Venusian Colonial Service. And then, without preamble, he had been sent to the most remote garrison in the Blue Swamp mold country—Post One.

A week after his arrival the Commandante had ordered him to ferret out a certain Kamali native who had rebelled against the Government, and disable him with a paralysis gun. Somehow when Simms had come face to face with the web-footed creature, his conscience had rebelled. Shooting in self-defense was one thing, but crippling in cold blood didn't seem human. He had let the Kamali go unharmed.

And a week later that same Kamali had sneaked through the impentration walls of the Post and murdered two Service men.

"The point is," Halleck continued, "we know where you stand, and we know we've got a good proposition ourselves. We've located a big Deleon mine near Xenthar village. That's deep mold country. All we have to do is start a little rebellion among the Kamali tribes, wait until they go on an expedition of war, then slip in and work the mine."

The man's eyes gleamed sardonically. But it was Gately who put the final offer into words.

"Now then, Simms," he said huskily, "you're getting a lousy deal from the government anyway. If you deliver that message, you'll only lose your commission. String along with us, and we'll treat you right. What do you say?"

Simms' face masked the battle that was waging in his soul.

"I'll think it over," he said at length.

Three hours later Simms lay in one of the wall bunks, wide awake. The jetty room was in semi-darkness, lit only by the soft glow that filtered through the ports. From the bunks opposite came the regular breathing of Halleck and Sterns. Gately sat by the table, smoking a cigarette.

The situation was quite clear to Simms now. He was a prisoner. The slightest attempt on his part to escape would result in the space-rats taking action. For it was to their interest that his message did not get through. Post One had asked for reinforcements. Those reinforcements coming back through the swamp would interfere with their plans to get the rejuvenation salts.

On the other hand Halleck had spoken the truth when he said that Simms was heading straight into disaster. Delivery of that sealed message cylinder would mean his immediate dismissal from the Venusian Colonial Service.

His hands dug into the blankets. Suppose he did throw in with these three. Halleck would see that a tribal war of large proportion got under way among the Kamalis at once. That would mean every garrison in Blue Swamp would be in danger of complete annihilation. Post One with its flimsy impentration walls and its men weakened by Mold Fever would be wiped out.

All because of a few crystals. For two generations those Deleon Salts had been a mystery to Earthmen who colonized Venus. Chemists only knew that the Kamalis used the drug to rejuvenate their bodies and prolong life.

Once in ages past the Kamalis had been a great race with a high culture. Then through some great catastrophe their numbers had been decimated and made sterile. Gradually they had migrated into Blue Swamp, and it was here no doubt that they had developed their webbed feet and their elongated ears. Yet while the Deleon Salts served to rejuvenate their bodies, their minds had gradually atrophied. Only the ruling Oligarchs knew the secret of using the drug without harm to their mental powers.

Abruptly Simms tensed. Across the room Gately's head nodded in sleep. The Venusian Service man slid to his feet, stole noiselessly across to the three ports and closed them. From his pocket he took a small paralysis-fume pellet, lit it and tossed it under the table.

Back in his own bunk, he pulled on his dehydration mask and waited tensely. In sixty seconds a grey fog of vapor was swirling through the room. In sixty seconds more Gately's body had become rigid, his right arm suspended in space over the table.

Simms made sure his message-tube was in its place in his belt holster. Then he crossed unchallenged to the door. An instant later he was outside, advancing along the catwalk.

He leaped into his jagua and began to paddle madly, intent only on putting distance between himself and the jetty.

He had two alternatives: to continue on to GHQ at BeTaba, or to head into forbidden mold country and warn Xenthar village. Either way his own future was doomed. But without hesitation he chose the latter.

Mile after mile Simms fought his way along hidden channels, each of which resembled its predecessor. At first he had no idea where Xenthar village lay. Then, in his mind's eye, he saw again that relief-map of the Blue Country which all Venusian Service men must commit to memory. Xenthar lay to the east in an unexplored district.

Huge blue priest trees bowed before him and sang their aeolian litanies as he passed. Living serpent-kelp clutched at his dugout and tried to prevent his passage. He moved by his watch. Overhead, at exact thirty minute intervals, successive hordes of Poleidons—Ithiosyoria—roared past in great blue clouds. As each migration came he ceased paddling and sat motionless. The slightest movement would have sent those flying lizard birds down to attack him.

Even his dehydration mask failed to keep out the odor of mold. Mold balls, two feet across, floated through the air like great puffs of bluish cotton. Simms kept a wary eye trained to see that none fell on the jagua. Had one done so, the sacrophytic spores would have taken root and over-run the boat in a matter of seconds.

On and on he went through the incessant rain. Once a huge waterskipper came, leaped over the surface of the water, its huge center eye open, its mouth a slavering slit of orange. He dug his paddle deep and pushed into the blue rip grass until the monster had passed.

And finally he saw it—a rectangular floating platform, constructed of mud and thatch, anchored by a network of vine cables.

He made a landing at a small wharf and began to stride along a matting path. Twenty feet forward, and he came face to face with a Kamali. The little man stopped short on his webbed feet, and his huge ears flapped ludicrously. With a low cry he turned and ran.

"I'm in for it now," Simms muttered. "That devil will warn the whole village."

His words were a prediction. Before he had gone fifty yards more a squad of Kamali guardsmen advanced upon him. They wore skins of Chabla cat and red headdresses formed of patani, the Venusian swamp flower.

But Simms, though new to the Service, had had experience with interior villages before. Quietly he handed over his heat gun, let his wrists be bound, permitted himself to be escorted down the walk.

The village opened before him. Simms saw a double row of rectangular huts formed of white carponium. In the center a round hut marked the quarters of the Oligarch and before this structure a taller Kamali stood, wearing a headdress formed of some brownish plastic.

Simms bowed and held his message-tube in his bound hands before him in the formality expected.

"Lieutenant Simms," he said, "Sixth Venusian Colonials, bound Post One to general headquarters at BeTaba. I bring you information, oh mighty one, which it will pay you to hear."

The Oligarch's eyes contracted. He motioned Simms to continue.

"Three Earth men," the lieutenant said, "are headed for your village. They...."

His voice died off. Behind the Oligarch three familiar figures suddenly appeared in the doorway. In the foreground stood Halleck, smoking a cigarette, eyes filled with triumph. Behind him lounged Gately and Sterns. The heat-gun scar on the latter's face seemed deeper and redder than before.

"I'm afraid you're too late, Simms," Halleck said. "I've already explained to his highness that you've come to this village to steal his Deleon Salts. I think you know what that means."

Gately laughed harshly. "You were pretty smooth back at the Jetty," he said. "But you forgot that the dehydrators would dispose of the fumes from your paralysis-pellet in a few moments. You forgot also that we travel by hydrocar."

Simms' fists clenched. Suddenly an overpowering urge to smash Halleck's sneering face blinded all his reason. Before the Kamali guards could restrain him, he threw himself forward and planted a driving blow into the space-rat's jaw with his two lashed fists.

But that was as far as Simms got. The Oligarch spoke a quick command then, and a rush of webbed feet sounded. Something heavy crashed down on the lieutenant's skull. He felt himself falling—into a pit of blackness.

Curiously, he was aware of no lapse of time when he opened his eyes. He lay on the floor of the a low ceilinged room that was bare of furnishings.

Dizziness claimed him, and it was several minutes before he could gather sufficient strength to stand erect. He headed first for the door. It was locked, and the two circular windows were both grilled with stout metal bars. For the second time in a few hours Simms was a prisoner.

He turned, surveyed the room with eyes of growing despair. An antiquated paralysis gun hang from a peg on one wall. He tore it free and flipped open the charge chamber. But as he had expected, it was green with mold and quite useless.

The circular windows opened out on the extreme end of the village. Peering between the bars, Simms saw an endless line of Kamalis padding in from the other side of a vine screen, depositing the contents of baskets on a growing pile of black slag. A dozen Kamalis squatted there, pounding pieces of the slag with little flat-nosed hammers.

This then was the Deleon Salt industry, the secret of which was so jealously guarded.

Abruptly Simms found his gaze focused on a larger conical building he had not noticed before. Even as he stared at its smooth windowless sides, a sound emerged from it. A low drone at first, it rapidly mounted the octaves until it became a high-pitched siren-like shriek. The sound pulsed through the walls of the hut, bludgeoned against the lieutenant's eardrums, seemed to eat into his very brain.

Higher and higher it mounted, until presently it had gone beyond the hearing range. But Simms got the impression it was still climbing into the supersonic range.

He saw then a native cross the square and head toward his hut, carrying a dish of food. The lieutenant glanced at the old-fashioned lock on the door, and a thought struck him. Feverishly he searched his pockets, drew forth his watch. Made for use on all planets, the timepiece had a magno-shielded case.

Quickly Simms unscrewed the back cover. The door creaked open, and the Kamali thrust the dish of food inside. But in the instant before the door clicked into position again, Simms had slipped the watch cover between the latch and the magnetic face plate.

The intervening hours until the light outside gradually faded seemed interminable. At length, however the square outside the hut was blanketed in deep gloom. Simms boldly opened the door and emerged onto the street.

Without a plan of any kind he headed instinctively toward the slag pile and the tower from which that strange vibration had come. He had reached the extreme end of the village when voices reached his ears. Quickly Simms darted into the doorway of a near hut. The men were Halleck and Gately!

"Why take chances?" Gately was saying. "We've got all the time in the world, and we might as well give those salts a longer vibration exposure. That way the Earth people who take the stuff won't feel any bad effects for maybe two years."

Halleck swore in reply. "You fool," he said. "Don't you realize we're working on counted time. The I.P. men are after me now on Mars and Jupiter. We've got to work fast. Have you convinced the Oligarch?"

Gately grunted. "Yes, the whole village sets out on an expedition of war tomorrow night."

"You told the Oligarch that neighboring tribes had been tampering with his Deleon mine?" There was growing satisfaction in Halleck's voice.

"Sure, I told him. Sterns told him, too, and the fool would be alive now if he'd taken precautions...."

The voices became inaudible then as the men passed on. Simms stood in his tracks undecidedly. Then a glimmer of flare lightning in the sodden sky illuminated that strange tower just ahead. Like a magnet it drew him forward with its power.

Crouching low, he reached its cylindrical sides. He was groping for the entrance when his hands touched something soft and yielding. Chilled, he waited for a second lightning flare.

It came, and it revealed the body of the third space-rat, Sterns. The man was dead. His eyes were bulging and streams of blood were issuing from either ear.

Bewildered, yet careful not to disturb the body, Simms completed his circle of the tower and found the entrance. Inside he felt rather than saw a spiral staircase leading upward. With the utmost caution he began to climb.

He was breathing hard when he reached the top. A door barred his way. Simms pushed it open and stood staring on the threshold.

A bluish radite lamp was suspended from the ceiling. Occupying a good half of the chamber was a huge parabolic horn, its small end converging on a platform upon which a circular disc slowly revolved. In the center of the disc was a rounded heap of yellow crystals.

The left wall was taken up by a switchboard, with a series of dials staggered across a corbite panel. At the right wall, facing the open end of the parabolic horn, was a large wire cage.

Simms strode forward. The crystals on the revolving disc were Deleon Salts. But what was the meaning of this other apparatus?

He peered inside the cage and stared, incredulously. Hudrites! The cage was filled with hundreds of the Venusian swamp insects.

And then abruptly something clicked in his brain like a puzzle piece fitting into a slot. This chamber housed the mechanism that made the rejuvenation salts adaptable to the Kamalis. The secret was vibration, a bombardment of supersonic waves, causing a basic mutation of the crystals' molecular structure.

The Hudrites were the Venus equivalent of the Earth cricket. But where a cricket gave off vibrations of 8,000 a second, the frequency of a Hudrite had never been measured. It was said to be more than two million cycles.

The vibrations from these insects were picked up by the parabolic horn and a sensitive detector and stepped up by a cyclestat. When the sound waves struck the crystals, they responded to it at their frequency and by its vibrations gave rise to a varying voltage. The sound waves of the Hudrites were thereby converted into electrical vibrations and these electrical waves amplified with the aid of vacuum tubes.

The two were then united, and this bombardment of supersonic and electrical waves changed the structure of the Deleon crystals. No doubt the Kamali Oligarchs had discovered through long experiment just how long a vibration exposure was necessary to make the salts potent and still not effect their mental powers. The process undoubtedly took months of Venus time.

But the space-rats, Halleck and Gately, had no intention of waiting that long. They planned to expose the crystals for the shortest possible time and then sell them to unsuspecting citizens of Earth.

Another thought struck Simms. Sterns! What had killed him?

He had the answer an instant later. Up on the wall a warning bell sounded and a red light flashed off and on. From a microtone speaker sounded that same deep-toned drone. Again it began to mount swiftly up the octaves, rising steadily to a high-pitched shriek preparing the way for the supersonic vibrations of the Hudrites. The lieutenant clapped his hands to his ears, fell to the floor in writhing agony.

Stabbing lancets of pain darted through his brain. He felt his eyes protruding; his head seemed ready to explode. With a mighty effort he managed to jerk on his dehydration mask, slide the protective ear-caps into place. Even then the sensation was only partly relieved, and he stood, heart pounding, waiting for the mad vibration to stop.

When at length it came to an end, a glance at the Deleon Salts showed him they had colored from a light yellow to a deep orange. Tiny facets of irridescent flame now played over their surfaces.

Whatever method of utilizing the supersonic field the Kamalis used, it was a deadly one. As the body of Sterns proved, the action of those piezo-electric crystals was fatal to the unprotected human organism.

Simms moved to the control panel. He had the secret of the Deleon Salts now. But what good would it do him. In a short time his escape would be detected and....

But even as his gaze sped over the dials, a thought struck him. One of those dials must control the intervals of time between each supersonic bombardment. Another must control the frequency of the vibrations.

Boldly Simms seized a rheostat and shoved it over to its farthest marking. He found the time dial and pushed that upward too, guessing at the length of increase.

Then he was descending swiftly the spiral staircase to the ground level. He skirted the main street of the village and groped his way through inky blackness to the swamp shore.

In the gloom he made out his jagua. But he didn't stop here. He ran blindly a hundred yards along the matting shore until a squat beetle-like shape materialized out of the darkness. The space-rats' hydrocar.

In a half minute he had the mooring line unfastened. And then splitting the darkness about him came a shaft of white light. Simultaneously Halleck's voice yelled:

"Get him before he gets into the car!"

There was a dull report like a melon striking, and something soft and fuzzy whizzed past Simms' head to hit the water with a hollow plop. A mold gun! In the relentless light of Halleck's search lamp, the lieutenant saw the living fungus erupt into a hundred wriggling spores that germinated in a matter of seconds.

Simms leaped into the cabin and fumbled for the starter switch. Once a dozen years before he had driven a hydrocar on a pleasure cruise a short distance up the Martian Central Canal. Now his fingers touched the stud, and the motor roared into life.

But before he could press the trigger out into the swamp, he saw Halleck leap through the water and hurl himself onto the car's hood. The man broke the windscreen into a hundred glass fragments and thrust a mold gun through the aperture straight into Simms' face.

But before he could press the trigger something happened. Back in Xenthar village a mighty wailing scream pierced the air. Like a frightened banshee the sound raced into the upper register, leaped to a grinding, ear-shattering shriek.

Halleck dropped the mold gun and clapped his hands to his ears. On shore the Kamalis uttered cries of pain and fell groveling as the sound mounted into the supersonic range and the piezo-electric crystals began their action.

With a jerk Simms swung the wheel, throwing Halleck off balance and plummeting him into the water. The hydrocar roared out into the swamp like a runaway comet.

All night Simms drove, weaving through aisles of man-high rip grass, circling denser groves of blue priest trees and ardaleptic ferns.

At dawn he drew up at a small island, built a fire and cooked some of the food he found packed away in a rear compartment of the hydrocar. He rested half an hour, reentered the car and drove on at a more leisurely speed.

There remained now only to go to GHQ at BeTaba, give his report and hand over his message-cylinder. And when the tube was opened, he would be through on Venus. Dismissed from the Service for insubordination. Wherever he went, that report would follow him.

His lips compressed. There was a girl waiting for him back on Earth—waiting until he had completed his hitch in the Service and could graduate to the spaceways.

Abruptly his hand, reaching to his belt, stopped, and an electric shock ran through him.

His message cylinder was gone! He must have lost it when he rested at the little island.

For a moment he sat motionless, a cold numbness sweeping over him. He must have that cylinder when he reported at BeTaba. That part of the message pertaining to reenforcements for the garrison would be given orally, of course. But the section regarding himself was different. If he failed to deliver that letter, sooner or later he would be accused of throwing it away. It would mean another case of—insubordination.

Suddenly he threw over the wheel and sent the hydrocar racing back in the direction from which it had just come.

The Great Swamp faded out of his vision now. He drove with his thoughts. And then as familiar landmarks began to rise up before him, he realized what he was doing.

It was selfishness that had driven him along the back trail. He was returning for a kind of personal satisfaction. Deliberately taking chances when the stakes were higher than himself or his own feelings.

But the island lay just ahead. It would be mad to turn back now that he had come this far. He ran the hydrocar into a little inlet, switched off the motor and climbed out.

The coals of his campfire were still glowing. Carefully he began to search the trampled grass. A fern writhed in the sodden wind, and a glint of metal caught his eye. The official tube lay where it had fallen, close to the shore.

But as Simms strode forward, a footstep sounded behind him. He stiffened and turned. An Earth man stood there on the little beach, hands resting triumphantly on hips, watching him.

"Halleck!"

In the swamp back of the space-rat lay a long akimla canoe, filled with Kamali tribesmen, drawn by three waterskippers, their ugly beetle-like bodies lashed with an intricate network of harness.

There was a mold gun in Halleck's hands, and he had it leveled before him.

Out of the corner of his eye the lieutenant was searching desperately for a way of escape. Above him his upraised hands touched the spreading branch of a priest tree, and he saw that its farther extremity hung within a foot of Halleck's gun hand.

Simms seized the branch and gave it a powerful downward jerk. And in the instant that the space-rat's weapon was pushed out of aim, he threw himself forward in a flying tackle.

He fought desperately, aware that he had seconds in which to act and no more. A heavy kick in the groin sent a wave of nausea surging through him. Then his hands closed about the mold gun. He tore it free and pounded a hard blow into the space-rat's jaw. Twice he stuck. Then as Halleck slumped backward, he stumbled erect and trained the weapon on the advancing Kamalis, finger tight on trigger.

"Back!" he snapped. "One move, and I fire. Get into that jitterbug chariot of yours and get going!"

Two days later a mud-stained, mold-encrusted hydrocar swung up to the jetty at BeTaba, Venusian Colonial Headquarters on the outer edge of Blue Swamp. Two haggard Earthmen climbed out, one still gripping a Kamali mold gun, the other, his hands bound behind him.

They paced down the catwalk, entered the lock, and a moment later stood before the Post Major. Simms saluted and began a graphic description of all that had occurred.

"Post One needs help sir," he concluded. "There were twelve cases of Mold Fever when I left, and the impentration walls are badly in need of repair. The Kamalis are on the verge of an intertribal war."

The Major looked the prisoner over and nodded. All the defiance was gone from Halleck now. He stood there, lips twisted in a sullen snarl, eyes mirroring defeat.

"The I.P. men have been after this rat for a long time," the Major said. "And now, Lieutenant, I'll have your official report."

Silently Simms handed the message cylinder across the desk.

The Major opened the cylinder and glanced at the scroll inside. A moment passed in silence as he read the message.

"Lieutenant," he said at length, looking up, "how long have you been at Post One?"

"Six weeks, sir."

The Major opened a humidor and took out a Martian cheroot. "It so happens your Commandante is a very shrewd person. Lieutenant, take a look at this letter."

Slowly Simms picked up the scroll and read:

... and am sending this letter by Lieutenant Simms, a newcomer to Post One. The boy had the usual case of nerves brought about by the damnable solitude, the rain and the constant dangers here at the post, and I'm taking the usual method of curing it. Let him rest over at BeTaba for a month. Then send him back. He has the makings ...

And across the desk the Major puffed his Martian cheroot and smiled.