Tommy Reames saw the red sun rise while he was on guard at the mouth of the Tube. The tree-ferns above him came into view as vague gray outlines. The many-colored stars grew pale. And presently a bit of crimson light peeped through the jungle somewhere. It moved along the horizon and very slowly grew higher. For a moment, Tommy saw the huge, dull-red ball that was the sun of this alien planet. Queer mosses took form and color in the daylight, displaying colors never seen on Earth. He saw flying things dart among the tree-fern fronds, and some were scaled and some were not, but none of them were feathered.

Then a tiny buzzing noise. The telephone that now rested below the lip of the Tube was being used from the laboratory.

“Smithers will relieve you,” said Denham’s voice in the receiver. “Come on down. We’re not the only people experimenting with the Fifth Dimension. Jacaro’s been working, and all hell’s loose!”

Tommy slid down the Tube in an instant. The four right-angled turns made him sick and dizzy again, but he came out with his jaw set grimly. There was good reason for Tommy’s interest in Jacaro. Besides sides three bullet wounds, Tommy owed Jacaro something for stealing the first model Tube.

He emerged in the laboratory on his hands and knees as the size of the Tube made necessary. Smithers smiled placidly at him and crawled in to take his place.

“What the devil happened?” demanded Tommy.Denham was bitter. He held a newspaper before him. Evelyn had brought coffee and the morning paper to the laboratory. She seemed rather pale.

“Jacaro’s gotten through too!” snapped Denham. “He’s gotten in a pack of trouble. And he’s loosed the devil on Earth. Here—look!” He jabbed his finger at one headline. “And here—and here!” He thrust at others. “Here’s proof.”

The first headline read: “KING JACARO FORFEITS BOND.” Smaller headings beneath it read: “Racketeer Missing for Income Tax Trial. $200,000 Bail Forfeited.” The second headline was in smaller type: “Monster Lizard Killed! Giant Meat Eater Brought Down by Rifleman. Akin to Ancient Dinosaurs, Say Scientists.”

“Jacaro’s missing,” said Denham harshly. “This article says he’s vanished, and with him a dozen of his most prominent gunmen. You know he had a model catapult to duplicate—the one he got from you. Von Holtz could arrange the construction of a big Tube for him. And he knew about the Golden City. Look!”

His finger, trembling, tapped on the flashlight picture of the giant lizard of which the story told. And it was a giant. A rope had upheld a colossal, leering, reptilian head while men with rifles posed self-consciously beside the dead creature. It was as big as a horse, and at first glance its kinship to the extinct dinosaurs of Earth was plain. Huge teeth in sharklike rows. A long, trailing tail. But there was a collar about the beast-thing’s neck.

“It had killed and was devouring a cow when they shot it,” said Denham bitterly. “There’ve been reports of these creatures for days—so the news story says. They weren’t printed because nobody believed them. But there are a couple of people missing. A searching party was hunting for them. They found this!”

Tommy Reames stared at the picture. His face went grimmer still. He thought of sounds he had heard beyond the Tube, not long since.

“There’s no question where they came from. The Fifth Dimension. But if Jacaro brought them back, he’s a fool.”

“Jacaro’s missing,” said Denham savagely. “Don’t you understand? He could get through to the Golden City. These beast-things are proof somebody did. And these things came down the Tube that somebody travelled through. Jacaro wouldn’t send them, but somebody did. They’ve got collars around their necks! Who sent them? And why?”

Tommy’s eyes narrowed.

“If civilized men found the mouth of a Tube, it would seem like the mouth of an artificial tunnel or a cave—”

“And if annoying vermin, like Jacaro’s gunmen”—Denham’s voice was brittle—“had come out of it, why, intelligent men might send something living and deadly down it, as men on Earth will send ferrets down a rat-hole! To wipe out the breed! That’s what’s happened! Jacaro’s gone through and attacked the Golden City. They’ve found his Tube. And they’ve sent these things down….”

“If we found rats coming from a rat-hole,” said Tommy very quietly, “and ferrets went down and didn’t come up, we’d gas them.”

“And so,” Denham told him, “so would the Golden City.”

He pointed to a boxed double paragraph news story under leaded twenty-point headline: “Poisonous Fog Kills Wild Life.”

The story was not alarming. It said merely that state game wardens had found numerous dead game animals in a thinly-settled district near Coltsville, N.Y., and on investigation had found a bank of mist, all of half a mile across, which seemed to have caused the trouble. State chemists and biologists were investigating the phenomenon. Curiously, the bank of mist seemed not to dissipate in a normal fashion. Samples of the fog were being analyzed. It was probably akin to the Belgian fogs which on several occasions had caused much loss of life. The mist was especially interesting because in sunlight it displayed prismatic colorings. State troopers were warning the inhabitants of the neighborhood.

“The gassing’s started,” said Denham savagely. “I know a gas that shows rainbow colors. The Golden City uses it. So we’ve got to find Jacaro’s Tube and seal it, or only God knows what will come out of it next. I’m going off, Tommy. You and Smithers guard our Tube. Blow it up, if necessary. It’s dangerous. I’ll get some authority in Albany, and we’ll find Jacaro’s Tube and blast it shut.”

Tommy nodded, his eyes keen and thoughtful. Denham hurried out.

Minutes later, only, they heard the roar of a car motor going down the long lane away from the laboratory. Evelyn tried to smile at Tommy.

“It seems terrible, dangerous.”

Tommy considered and shrugged.

“This news is old,” he observed. “This paper was printed last night. I think I’ll make a couple of long-distance calls. If the Golden City’s had trouble with Jacaro, it’s going to make things bad for us.”

He swept his eyes about and frowningly loaded a light rifle. He put it convenient to Evelyn’s hand and made for the dwelling-house and the telephone. It was odd that as he emerged into the open air, the familiar smells of Earth struck his nostrils as strange and unaccustomed. The laboratory was redolent of the tree-fern forest into which the Tube extended. And Smithers was watching amid those dank, incredible carboniferous-period growths now.

Tommy put through calls, seeing all his and Denham’s plans for a peaceful exploration party and amicable contact with the civilization of that other planet, utterly shattered by presumed outrages by Jacaro. He made call after call, and his demands for information grew more urgent as he got closer to the source of trouble. His cause for worry was verified long before he had finished. Even as he made the first call, New York newspapers had crowded a second-grade murder off their front pages to make room for the white mist upstate.

The early-morning editions had termed it a “poisonous fog.” The breakfast editions spoke of it as a “poison fog.” But it grew and moved and by the time Tommy had a clear line to get actual information about it, a tabloid had christened it the “Death Mist” and there were three chartered planes circling about it for the benefit of their newspapers. State troopers were being reinforced. At ten o’clock it was necessary to post extra traffic police to take care of the cars headed upstate to look at the mystery. At eleven it began to move! Sluggishly, to be sure, and rather raggedly, but it undoubtedly moved, and as undoubtedly it moved independently of the wind.

It was at twelve-thirty that the first casualty occurred. Before that time, the police had frantically demanded that the flood of sightseers be stopped. The Death Mist covered a square mile or more. It clung to the ground, nowhere more than fifty or sixty feet high, and glittered with all the colors of the rainbow. It moved with a velocity of anywhere from ten to twenty miles an hour. In its path were a myriad small tragedies—nesting birds stiff and still, and rabbits and other small furry bodies contorted in queer agonized postures. But until twelve-thirty no human beings were known to be its victims.

Then, though, it was moving blindly across the wind with a thin trailing edge behind it and a rolling billow of descending mist as its forefront. It rolled up to and across a concrete highway, watched by perspiring motor cops who had performed miracles in clearing a path for it among the horde of sightseeing cars. It swept on into a spindling pine wood. Behind it lay a thinning sheet of vapor—thick white mist which seemed to rise and move more swiftly to overtake the main body. It lay across the highway in a sheet which was ten feet deep, then thinned to six, to three….

The mist was no more than a foot thick, when a party of motorists essayed to drive through it as through a sheet of water. They dodged a swearing motorcycle cop and, yelling hilariously, plunged forward. It happened that they had not more than a hundred yards to go, so the whole thing was plainly seen.

The car was ten yards across the sheet of mist before the effect of its motion was apparent. Then the mist, torn by the car-eddy, swirled madly in their wake. The motorists yelled delightedly. There is a picture extant, taken at just this moment. It shows the driver with a foolish grin on his face, clutching the wheel and very obviously stepping on the accelerator. A pandemonium of triumphant, hilarious shouting—and then a very sudden silence.

The car roared on. The road curved slightly. The car did not. It went off the road, turned over, and its engine shrieked itself into silence. The Death Mist went on, draining from the roadway to follow the tall, prismatically-colored cloud. It moved swiftly and blindly. To the circling planes above it, it seemed like a blind thing imagining itself confined, and searching for the edges of its prison. It gave an uncanny impression of being directed by intelligence. But the Death Mist, itself, was not alive.

Neither were the occupants of the motor car.

When Tommy got back to the laboratory after his last call for news, he found Evelyn in the act of starting to fetch him.

“Smithers called,” she said uneasily. “He says something’s moving about—” The buzzer of the telephone was humming stridently. Tommy answered quickly.

“Just want you handy,” said Smithers’ calm voice. “I might have to duck. Some Ragged Men are chasin’ something. Get set, will ya?”

“Ready for anything,” Tommy assured him.

Then he made it true: rifles handy, a sub-machine gun, grenades, gas masks. He handed one to Evelyn. Smithers had one already. Then Tommy waited, grimly ready by the Tube-mouth.

The warm, scent-laden breeze blew upon him. Straining his ears, he could hear the sound of tree-fern fronds clashing in the wind. He heard the louder sounds made by Smithers, stirring ever so slightly in the Tube. And then he caught a vague, distant uproar. It would have been faint and confused at best but the Tube was partly blocked by Smithers’ body, and there were the multiple bends further to complicate the echoes. It was no more than a formless tumult through which faint yells came occasionally. It drew nearer and nearer. Tommy heard Smithers stir suddenly, almost as if he had jumped. Then there were scrapings which could only mean one thing: Smithers was climbing out of the Tube into the jungle of the Fifth-Dimension world.

The noise rose abruptly to a roar as the muffling effect of Smithers’ body was removed. The yells were sharp and savage and half mad. There was a sudden crackling sound and a voice screamed:

“Gott!”

The hair rose at the back of Tommy’s neck. Then there came the deafening report of an automatic pistol roaring itself empty above the end of the Tube. Smithers’ voice, vastly calm:

“It’s a’right, Mr. Reames. Don’t worry.”

A second pistol took up the fusillade. Yells and howls and screams arose. Men fled. Something came crashing to the mouth of the Tube. Smithers’ voice again, with purring note in it: “Get down there. I’ll hold ’em off.” Then single deliberately spaced shots, while something came stumbling, fumbling, squirming down through the Tube, so filling it that Smithers’ shooting was muted.

Then came the subtly different explosions of the Very pistols, discharging gas bombs. And Tommy drew back, his jaw set, and he stood with his weapons very ready indeed, and a scratched, bleeding, exhausted, panting, terror-stricken human being in the tattered costume of Earth crawled from the Tube and groveled on the floor before him.

Evelyn gave a little exclamation, partly of disgust and partly of horror. Because this man, who had had come from the world of the Fifth Dimension, was wholly familiar. He was tall, and he was lean, emaciated now; he wept sobbingly behind thick-lensed spectacles, and his lips were far too full and red. His name was Von Holtz; he had once been laboratory assistant to Professor Denham, and he had betrayed Evelyn and her father to the most ghastly of possible fates for a bribe offered him by Jacaro. Now he groveled. He was horrible to look at. Where he was not scratched and torn his flesh was reddened as if by fire. He was exhausted, and trembling with an awful terror, and he gasped out abject, placatory ejaculations and suddenly collapsed into a sobbing mass on the floor.

Smithers emerged from the Tube with a look of unpleasant satisfaction on his face.

“I chased off the Ragged Men with sneeze gas,” he observed with a vast calmness. “They ain’t comin’ back for a while. An’ I always wanted to break this guy’s neck. I think I’ll do it now.”

“Not till I’ve questioned him,” said Tommy savagely. “He and Jacaro have started hell to popping, with that Tube design they stole from me. He’s got to stay alive and tell us how to stop it. Von Holtz, talk! And talk quick, or back you go through the Tube for the Ragged Men to work on!”