A three-dimensional map of the Solar System would have the appearance of a rather flat plate. In the center would be the Sun, the dominant member of the System. It is really dominant, since it contains 99.8% of all the matter in the Solar System. In other words, it weighs five hundred times as much as everything else in the Solar System put together.

Around the Sun circle the planets. All of them revolve in nearly the same plane, and this plane is called the Ecliptic.

In traveling from planet to planet space-ships usually follow the Ecliptic. In doing so they are within the main sub-etheric beams of planetary communication and can most conveniently make intermediate stops on the way to their destination. Sometimes, when a ship is interested in speed or in escaping detection, it veers away from the Ecliptic, particularly when it must travel to the other side of the Sun.

This, Lucky thought, might be what Anton's ship was intending to do. It would lift up from the "plate" that was the Solar System, make a huge arc or bridge above the Sun, and come down to the "plate" on the other side, in the neighborhood of Ganymede. Certainly Anton must have started in that direction, or the defending forces on Ceres wouldn't have missed filming him. It was almost second nature for men to make all spationautical observations along the Ecliptic first of all. By the time they thought of turning away from the Ecliptic, Anton would have been too far away for observation.

But, thought Lucky, the chances were that Anton would not leave the Ecliptic permanently. He might have started out as though that would be the case, but he would return. The advantages in a return would be many. The asteroid belt extended completely about the Sun, in the sense that asteroids were evenly distributed all the way around. By keeping within the belt Anton could remain among the asteroids all the way to within a hundred million miles or so of Ganymede. This would mean security for him. The Terrestrial government had virtually abdicated its power over the asteroids and, except for the routes to the four large rocks, government ships did not penetrate the area. Moreover, if one did, Anton would always be in the position of being able to call for reinforcements from some nearby asteroidal base.

Yes, thought Lucky, Anton would remain in the belt. Partly because he thought this, and partly because he had his own plans, Lucky lifted the Shooting Starr out of the Ecliptic in a shallow arc.

The Sun was the key. It was the key to the entire System. It was a roadblock and a detour to every ship man could build. To travel from one side of the System to another, a ship had to make a wide curve to avoid the Sun. No passenger ship approached closer than sixty million miles, the distance of Venus from the Sun. Even there, cooling systems were imperative for the comfort of the passengers.

Technical ships could be designed to make the trip to Mercury, the distance of which from the Sun varied from forty-three million miles in some parts of its orbit to twenty-eight million in others. Ships had to hit it at the furthest region of its retirement from the Sun. At closer than thirty million miles various metals melted.

Still more specialized ships were sometimes built for close-by solar observation. Their hulls were permeated by a strong electric field of peculiar nature which induced a phenomenon known as "pseudo-liquefaction" in the outermost molecular skin. Heat reflection from such a skin was almost total, so that only a tiny fraction penetrated into the ship. From outside such ships would appear perfect mirrors. Even so, enough heat penetrated to raise the temperature within the ship above the boiling point of water at distances of five million miles from the Sun, the closest recorded approach. Even if human beings could survive such a temperature, they couldn't survive the short-wave radiation that flooded out of the Sun and into the ship at such distances. It could kill anything living in seconds.

The disadvantage of the Sun's position with respect to space travel was obvious in the present instance, in which Ceres was on one side of the Sun while Earth and Jupiter were almost diametrically opposed on the other side. If one was in the asteroid belt, the distance from Ceres to Ganymede was about one billion miles. If the Sun could be ignored and a ship could cut straight across space through it, the distance would be only six hundred million miles, a saving of about forty per cent.

This, as far as was possible, Lucky intended to do.

He drove the Shooting Starr hard, virtually living in his g-harness, eating and sleeping there, feeling the pressure of acceleration continuously. He gave himself only fifteen minutes respite out of each hour.

He passed high above the orbits of Mars and Earth, but there was nothing to see there, not even with the ship's telescope. Earth was on the other side of the Sun, and Mars was at a position nearly at right angles to his own.

Already the Sun was at its normal size as seen from Earth and he could view it only through the most strongly polarized visiplates. A little more and he would have to use the stroboscopic attachments.

The radioactivity indicators began to chuckle occasionally. Within Earth's orbit the density of short-wave radiation started to reach respectable values. Inside Venus's orbit special precautions would have to be taken, such as the wearing of lead-impregnated semi-space-suits.

I, myself, thought Lucky, would have to do better than lead. At the approach to the Sun that he would have to make, lead would not do. Nothing material would do.

For the first time since his adventure on Mars the previous year Lucky drew out of a special pouch glued to his waist, the flimsy, semitransparent object obtained from the Martian energy beings.

He had long since abandoned any effort at speculation as to the method by which the object worked. It was the development of a science that had continued for a million years longer than the science known to Mankind and along alien paths. It was as incomprehensible to him as a space-ship would be to a cave man, and as impossible to duplicate. But it worked! That was what counted!

He slipped it on over his head. It molded itself to his skull as though it carried a strange life of its own, and as it did so, light gleamed out all over him. Over his body it was a glimmer like a billion fireflies, and it was for that reason that Bigman referred to it as a "glimmer shield." Over his face and head it was a solid sheet of brilliance that covered his features entirely, without, on the other hand, preventing light from reaching his eyes.

It was an energy shield, designed by the alien Martians for Lucky's needs. That is, it was impervious to all forms of energy other than that required by his body, such as a certain intensity of visible light and a certain amount of heat. Gases penetrated freely, so that Lucky could breathe, and heated gases, in passing, were robbed of their heat and came through cool.

When the Shooting Starr passed the orbit of Venus, still heading in toward the Sun, Lucky put on his energy shield permanently. While he wore it, he would not be able to eat or drink, but the enforced fast would not last for more than a day, at the outside.

He was now traveling at a terrific speed, far greater than any he had previously experienced. In addition to the slugging pull of the hyperatomics of the Shooting Starr, there was the unimaginable attraction of the Sun's giant gravitational field. He was traveling at millions of miles an hour now.

He activated the electric field that rendered the outer skin of the ship pseudo-liquid and was grateful, as he did so, for the foresight that had made him insist on that accessory during the building of the Shooting Starr. The thermocouple which had been registering temperatures above one hundred degrees began to show a drop. The visiplates went dark as metal shields passed over the thick glassite to keep them from damage and from softening in the heat of the Sun.

By the time Mercury's orbit was reached the radiation counters had gone completely mad. Their chatter was continuous. Lucky placed a glimmering hand over their windows and their noise stopped. Down to the hardest gamma rays the radiation penetrating and filling the ship was stopped by the resistance of the insubstantial aura that surrounded his body.

The temperature which had reached a low of eighty, was climbing again, despite the mirror skin of the Shooting Starr. It passed one hundred fifty and still went up. The gravimetrics indicated the Sun to be only ten million miles away.

A shallow dish of water, which Lucky had placed upon the table, and which had been steaming for an hour past, was now bubbling outright. The thermocouple reached the boiling point of water, two hundred and twelve degrees.

The Shooting Starr, whipping about the Sun, was now five million miles away. It would approach no closer. Actually it was inside the outermost wisps of the most rarefied portion of the Sun's atmosphere, its corona. Since the Sun was gaseous through and through (though most of it was a gas the like of which could not exist even under the most extreme laboratory conditions on Earth), it had no surface, and its "atmosphere" was part of the very body of the Sun. By going through the corona, then, Lucky was, in a way, going through the Sun, as he had told Bigman he would.

Curiosity tugged at him. No man had ever been this close to the Sun. No man, perhaps, ever would again. Certainly, any man who did, could not look at the Sun with his unaided eyes. The shortest possible glimpse of the Sun's tremendous radiation at that distance would mean instant death.

But he was wearing the Martian energy shield. Could it handle solar radiation at five million miles? He felt he ought not take the chance and yet the impulse tugged desperately at him. The ship's chief visiplate was outfitted with a stroboscopic outlet-series, one which would expose, one by one, each of a series of sixty-four outlets to the Sun, each for a millionth of a second every four seconds. To the eye (or to the camera), it would seem a continuous exposure, but actually any given piece of glass would only get one four millionth of the radiation the Sun was emitting. Even that required specially designed, nearly opaque lenses.

Lucky's fingers moved remorselessly, almost without conscious volition, to the controls. He could not bear the thought of losing the chance. He adjusted the plate direction toward the Sun, using the gravimetrics as indicators.

Then he turned his head away and plunged the contact home. A second passed, then two seconds. He imagined an increase in heat on the back of his neck; he half-waited for radiation death. Nothing happened.

Slowly he turned.

What he saw was to stay with him the rest of his life. A bright surface, puckered and wrinkled, filled the visi-plate. It was a portion of the Sun. He could not see the whole, he knew, in the visiplate, for at his distance, the Sun was twenty times as wide as it seemed from Earth and covered four hundred times as much of the sky.

Caught in the visiplate were a pair of sunspots, black against the brightness. Threads of glowing white curled into it and were lost. They were heaving areas of activity that moved across the plate visibly as he watched. This was not due to the Sun's own motion of rotation, which, even at its equator, was not more than fourteen hundred miles an hour, but rather to the tremendous velocity of the Shooting Starr.

As he watched, gouts of red, naming gas shot up toward him, dim against the blazing background, and turning a smoky black as it receded from the Sun and cooled.

Lucky shifted the plate, catching a portion of the rim of the Sun, and now the flaming gas (which were the so-called "prominences," consisting of gigantic puffs of hydrogen gas) stood out sharply crimson against the black of the sky. They spread outward in slow motion, thinning and taking on fantastic shapes. Lucky knew that each one of them could engulf a dozen planets the size of Earth, and that the Earth could be dropped into the sunspot he saw without even making a respectable splash.

He closed the stroboscopics with a sudden movement. Even though physically safe, no man could stare at the Sun from that distance without becoming oppressed by the insignificance of Earth and all things Earthly.

* * *

The Shooting Starr had whipped half around the Sun and was now receding rapidly past the orbits of Mercury and Venus. It was decelerating now. The ship's prow opposed the direction of its flight and its powerful main engines were acting as brakes.

Once past Venus's orbit, Lucky removed his shield and stowed it away. The ship's cooling system strained to get rid of the excess heat. Drinking water was still uncomfortably hot and the canned foods bulged where liquid within had bubbled into gas.

The Sun was shrinking. Lucky looked at it. It was an even, glowing sphere. Its irregularities, its churning spots, and heaving prominences could no longer be seen. Only its corona, always visible in space, though visible on Earth only during eclipses, thrust out in every direction for millions of miles. Lucky shuddered involuntarily to think that he had passed through it.

He passed within fifteen million miles of Earth, and through his telescope he spied the familiar outlines of the continents peeping through the ragged white masses of cloud banks. He felt a twinge of homesickness and then a new resolve to keep war away from the teeming, busy billions of human beings that inhabited that planet, which was the origin of all the men that now occupied the far-flung star systems of the Galaxy.

Then the Earth, too, receded.

Past Mars and back into the asteroid belt, Lucky still aimed at the Jovian system, that miniature solar system within the greater one. At its center was Jupiter, larger than all the other planets combined. About it swung four giant moons, three of them, lo, Europa, and Callisto, about the size of the Earth's Moon, and the fourth, Ganymede, much larger. Ganymede, in fact, was larger than Mercury, and almost as large as Mars. In addition there were dozens of moonlets, ranging from some hundreds of miles in diameter down to insignificant rocks.

In the ship's telescope Jupiter was a growing yellow globe, marked with faintly orange stripes, one of which bellied out into what was once known as the "Great Red Spot." Three of the main moons, including Ganymede, were on one side, the fourth was on the other.

Lucky had been in guarded communication with the Council's main offices on the Moon for the better part of a day now. His Ergometrics probed space with widely stretching fingers. It detected many ships, but Lucky watched only for the one with the Sirian motor pattern which he would recognize with certainty the instant it appeared.

Nor did he fail. At a distance of twenty million miles, the first quiverings roused his suspicions. He veered in the proper direction, and the characteristic curves grew more pronounced.

At one hundred thousand miles, his telescope showed it as a faint dot. At ten thousand, it had form and shape and was Anton's ship.

At a thousand miles (with Ganymede still fifty million miles away from both ships), Lucky sent out his first message, a demand that Anton turn his ship back toward Earth.

At one hundred miles Lucky received his answer-a blast of energy that made his generators whine and shook the Shooting Starr as though it had collided with another ship.

Lucky's tired face took on a drawn look.

Anton's ship was better-armed than he had expected.