another invasion by the black mold, not to mention the amoebae and other fabulous monsters that had up to now been kept at a safe distance by the repeller zone, a simple adaptation of a very old discovery. A zone of mechanical vibrations, of a frequency of 500,000 cycles per second, was created by a large quartz crystal in the water, which was electrically operated. Without power, the protective zone had vanished.

"We watch?" asked Gunga.

"You bet we watch. Every minute of the 'day' and 'night.'"

He examined the two chronometers, assuring himself that they were well wound, and congratulated himself that they were not dependent on the defunct power plant for energy. They were his only means of measuring the passage of time. The sun, which theoretically would seem to travel round and round the horizon, rarely succeeded in making its exact location known, but appeared to shift strangely from side to side at the whim of the fog and water.

"Th' fellas," Gunga remarked, coming out of a study. "Why not come?" He referred to the Inranians.

"Probably know something's wrong. They can tell the quartz oscillator is stopped. Afraid of the Ul-lul, I suppose."

"'Squeer," demurred the Martian. "Ul-lul not bother fellas."

"You mean it doesn't follow them into the underbrush. But it would find tough going there. Not enough water; trees there, four hundred feet high with thorny roots and rough bark—they wouldn't like that. Oh no, these natives ought to be pretty snug in their dens. Why, they're as hard to catch as a muskrat! Don't know what a muskrat is, huh? Well, it's the same as the Inranians, only different, and not so ugly."

or the next six days they existed in their straitened quarters, one guarding while the other slept, but such alarms as they experienced were of a minor nature, easily disposed of by their flash pistol. It had not been intended for continuous service, and under the frequent drains it showed an alarming loss of power. Forepaugh repeatedly warned Gunga to be more sparing in its use, but that worthy persisted in his practice of using it against every trifling invasion of the poisonous Inranian cave moss that threatened them, or the warm, soggy water-spiders that hopefully explored the ventilator shaft in search of living food.

"Bash 'em with a broom, or something! Never mind if it isn't nice. Save our flash gun for something bigger."

Gunga only looked distressed.

On the seventh day their position became untenable. Some kind of sea creature, hidden under the ever-replenished storm waters, had found the concrete emplacements of their trading post to its liking. Just how it was done was never learned. It is doubtful that the creatures could gnaw away the solid stone—more likely the process was chemical, but none the less it was effective. The foundations crumbled; the metal shell subsided, rolled half over so that silty water leaked in through the straining seams, and threatened at any moment to be buffeted and urged away on the surface of the flood toward that distant vast sea which covers nine-tenths of the area of Inra.

"Time to mush for the mountains," Forepaugh decided.

Gunga grinned. The Mountains of Perdition were, to his point of view, the only part of Inra even remotely inhabitable. They were sometimes fairly cool, and though perpetually pelted with rain, blazing with lightning and reverberating with thunder, they had caves that were fairly dry and too cool for the black mold. Sometimes, under favorable circumstances on their rugged peaks, one could get the full benefit of the enormous hot sun for whose actinic rays the Martian's starved system yearned.

"Better pack a few cans of the food tablets," the white man ordered. "Take a couple of waterproof sleeping bags for us, and a few hundred fire pellets. You can have the flash pistol; it may have a few more charges in it."

orepaugh broke the glass case marked "Emergency Only" and removed two more flash pistols. Well he knew that he would need them after passing beyond the trading area—perhaps sooner. His eyes fell on his personal chest, and he opened it for a brief examination. None of the contents seemed of any value, and he was about to pass when he dragged out a long, heavy, .45 caliber six-shooter in a holster, and a cartridge belt filled with shells. The Martian stared.

"Know what it is?" his master asked, handing him the weapon.

"Gunga not know." He took it and examined it curiously. It was a fine museum piece in an excellent state of preservation, the metal overlaid with the patina of age, but free from rust and corrosion.

"It's a weapon of the Ancients," Forepaugh explained. "It was a sort of family heirloom and is over 300 years old. One of my grandfathers used it in the famous Northwest Mounted Police. Wonder if it'll still shoot."

He leveled the weapon at a fat, sightless wriggler that came squirming through a seam, squinting unaccustomed eyes along the barrel. There was a violent explosion, and the wriggler disappeared in a smear of dirty green. Gunga nearly fell over backward in fright, and even Forepaugh was shaken. He was surprised that the ancient cartridge had exploded at all, though he knew powder making had reached a high level of perfection before explosive chemical weapons had yielded to the newer, lighter, and infinitely more powerful ray weapons. The gun would impede their progress. It would be of very little use against the giant Carnivora of Inra. Yet something—perhaps a sentimental attachment, perhaps what his ancestors would have called a "hunch"—compelled him to strap it around his waist. He carefully packed a few essentials in his knapsack, together with one chronometer and a tiny gyroscopic compass. So equipped, they could travel with a fair degree of precision toward the mountains some hundred miles on the other side of a steaming forest, a-crawl with feral life, and hot with blood-lust.

an and master descended into the warm waters and, without a backward glance, left the trading post to its fate. There was not even any use in leaving a note. Their relief ship, soon due, would never find the station without radio direction.

The current was strong, but the water gradually became shallower as they ascended the sloping rock. After half an hour they saw ahead of them the loom of the forest, and with some trepidation they entered the gloom cast by the towering, fernlike trees, whose tops disappeared in murky fog. Tangled vines impeded their progress. Quagmires lay in wait for them, and tough weeds tripped them, sometimes throwing one or another into the mud among squirming small reptiles that lashed at them with spiked, poisonous feet and then fell to pieces, each piece to lie in the bubbling ooze until it grew again into a whole animal.

Several times they almost walked under the bodies of great, spheroidal creatures with massive short legs, whose tremendously long, sinuous necks disappeared in the leafy murk above, swaying gently like long-stalked lilies in a terrestial pond. These were azornacks, mild-tempered vegetarians whose only defense lay in their thick, blubbery hides. Filled with parasites, stinking and rancid, their decaying covering of fat effectively concealed the tender flesh underneath, protecting them from fangs and rending claws.

Deeper in the forest the battering of the rain was mitigated. Giant neo-palm leaves formed a roof that