Nevertheless, from that point on, a different spirit seemed to animate everyone aboard the Magellan. There was the feeling that they had closed with the enemy and found themselves not wanting. There was the feeling that they possessed powers not inferior to those of their unknown enemies. The thought had been haunting them all along that they were in the position of a backward people facing an advanced invader—something like the problem of the Aztecs when faced with the gunpowder and armor of the conquistadors.

Now they knew that though the Sun-tappers' weapons were different and indeed advanced beyond Earthly technology, they themselves were not without resources equally deadly to the foe.

After the memory of the H-bomb's powers had been finally absorbed, the crew's activities began to indicate that the ship was coming into the crucial phase of its journey. Haines and Boulton were going over the list of military supplies with sharp, calculating eyes and slight grins at the thought of retribution to come. Ferrati was overhauling the rocket planes and land traveling devices, making them shipshape.

Russell Clyde and Burl surveyed the sky, anxious to be the first to spot what they hoped would be the limping body of the battered and fleeing dumbbell ship, a little atingle at the hope of spotting another such ship—feeling now almost like the hunting dog that has finally spotted the fox.

Lockhart himself reflected this mood of growing excitement. He prowled the ship, examining the mighty purring engines, querying Caton, Shea and Detmar as to how it could better its performance, how fast it could be made to shift speed and directions. He studied the orbits and locations of the remaining planets.

"Uranus is not too far off our path to Pluto," he announced one day. "We'll make it in time to wipe out their plant there. But Neptune, whose orbit is between those of Uranus and Pluto, is away off our track, a third of the way around the Sun. We're going to skip it, hit directly for Pluto and their main base—the end of their line. I don't want to give them too much time to make repairs or to get any reinforcements. I think they're limited in numbers—and we ought to slam them while they still are."

There was no dissent at this. And as the days rolled past, the men of the Magellan began to chafe in their repressed desire to finish the matter. At last Uranus came into sight—a large globe, very much like Saturn and Jupiter in that it was of low density and great dimensions. Roughly, sixty-four times the size of Earth, its density was barely above that of water and it probably had no solid surface to speak of. An inhospitable mass of unbreathable gases, at temperatures fantastically lower than the freezing point of water.

As they drew close to the planet, they could see that it also was banded, pale green bands alternating with lighter ones—indicating that some sections of its atmospheric belt moved faster than others. It had five moons which rotated in the opposite direction from those of any other satellite system.

It was on the farthest moon, Oberon, a sphere six hundred miles in diameter, that the Sun-tap station revealed itself. They swung down to observe it and to place their bomb. Not an H-bomb though—they recognized that they had erred in thinking they needed such a powerful explosive.

Oberon was without an atmosphere, a rocky world with streaks of frozen gases, and here and there the sheen of a lake of ice—ice that would never melt—that on this world would be a permanent, hard-as-metal material. There was, nonetheless, something about the surface that seemed to bother Russ.

"Do you notice what seems to be a sort of shifting movement?" he asked Burl. Burl looked, and sure enough, he saw that in places there seemed a flickering of lights.

"Yes," he said, "I see it. What do you suppose it is?"

"I don't know," said Russ, "But I'm going to ask Lockhart to put the ship down and let me take a look."

Lockhart at first demurred, but finally decided that they could afford the brief halt. The Magellan approached the surface, safely distant from the Sun-tap station.

Burl and Russ descended in the two-man rocket plane, while the teardrop-shaped ship hung half a mile above them. They landed on a narrow plain, bordered by low ridges of mountains shining with streaks of frozen hydrogen. A layer of cosmic dust hung over the rocks.

Wearing insulated space suits, they left the rocket plane. It was Burl who made the first discovery. He pointed dramatically at the ground. "Look, Russ. This dust is full of streaks and marks. It hasn't been lying here undisturbed. Something has crossed over it!"

Russ kneeled in order to look more carefully. The layer of dust, the consequences of an airless world exposed without protection to the endless fall of cosmic particles, was indeed not the level, undisturbed surface it should have been. Here and there were light, low depressions, as if something had moved across it—like a small snake crawling on its belly. In one place lay a series of depressions, like the footprints of some light-bodied creature.

"Impossible," muttered Russ. "Life can't exist here."

But they trudged on, across the barren flat to a ridge of rock. Here they found what they had thought to be impossible. Clustered along the side of the ridge, in the faint light of the distant and tiny Sun, was a series of thin, blue stalks, about half a foot in height. On each stalk was a flat scalloped top like a little umbrella. It was sometimes bright blue, and sometimes violet. As they drew nearer, these little stalks began to sway, and turned their tops toward them.

"They look like plants," said Burl. "Plants made of something glassy and plastic."

As Russ studied the strange growths, something moved across the dusty tract behind them. It was long and thin and wiggly, with a ridge of tiny crystalline hairs along its back. It was like a snake perhaps, but one made of some unbelievably delicate glasswork.

It slid among the plants and wrapped itself around one. The growth snapped suddenly, and then was absorbed by the creature.

Russ shook his head in amazement. "This is a great discovery," he said incredulously. "This is life! It's life of a chemical type utterly different from the protoplasm of Earth and Mars and Venus. It's life designed to exist among liquid gases and frozen air—life which can't have anything in common with protoplasm. Apparently it couldn't exist even on Saturn's moons—they were too hot for it!"

Russ was carried away with the possibilities. "This hints at great things, Burl. Out near Pluto, where the system is even colder, there may be other forms of this frigi-plasmic life, if I may coin a word. This means a whole new science!"

They returned to the ship with their astonishing news. The Magellan slowly skimmed over the surface of Oberon. They found whole forests of this glassy frigid vegetation, but not much evidence of any animal life larger than the creature the two explorers had seen.

Over the Sun-tap station—a ringed layout like the others, whose cluster of masts caught the emanations of the distant Sun on the one hand and directed them outward to the still unseen planet Pluto on the other—the ship halted. It drew up fifty miles, pointed its tail and blasted forth a rocket-driven, tactical atomic bomb.

The blast on Oberon was tiny compared to the one which had devastated Iapetus, but it still left a deep indentation in the surface for future space fliers to see.

They left it and the Uranian orbit behind them and headed outward once again. Behind them now lay the worlds of the Sun's family, while far off to one side lay the tiny light of Neptune. Ahead, between them and the vast gulf of interstellar space, lay only the dark, mysterious ninth planet, the enigmatic world named after the lord of the underworld, Pluto.

The Magellan plunged on, in constant acceleration, moving outward to the farthest limit of the solar system. They had traveled almost one billion, eight hundred million miles from the Sun—and yet they still had two billion miles more to go. This was the longest stretch—and during it, they would reach speeds greater than any they had touched before. They shot outward, faster and faster, eating up the infinite emptiness of space, driving the vast stretch that divided Pluto from its neighbors.

The Sun, already small, dwindled steadily. It was still the brightest star in their sky—of all the stars, it alone retained a disclike shape, and the faint flicker of its coronal flames could occasionally be made out—but it no longer dominated the heavens. To find the Sun, they now had to look for it as they would for any other star.

As for Earth, it could not be seen. So close to the tiny Sun it lay that only their sharpest telescopes could bring it out. Even Jupiter showed up only as a thin, tiny crescent near the solar point of light.

"Pluto's a mysterious world," said Burl as he and Russ scanned the heavens for a first glimpse of it. "The accounts in your astronomy books give very little real information on it—but what they give is strange. They say it's the only planet beyond Mars that is a small solid world like the inner ones. It seems to be the same size as Earth—not at all like the big outer worlds. And they say it seems to be the same mass as Earth—a solid world whose surface gravity would be the same as our own planet's."

Russ nodded. "It's an odd one, all right. There's now even some belief that it's not a true planet, but one that was once a satellite of Neptune. Its orbit is peculiar; it apparently may cut into that of Neptune. In fact, everything hints at Pluto not being a true child of our Sun. It may be a world captured from afar—a lonely wanderer cast off from some other star, captured by the Sun after millions of years of drifting lightless through space."

Beyond them, in their vision, lay only the stars of outer space, the void that did not belong to our system. And then, finally, they found Pluto—a tiny point of light shining among the blazing stars. They saw the disc, dimly reflected in the light of the far-away Sun.

Even as they were taking their first long look at the dark planet, the general alarm rang. They had caught up with the fleeing wreck of the Sun-tapper's scout cruiser.