Its coming had been observed. Men wearing the uniforms of the Martian army dashed out, their pistols ready. A man dropped out of a gaping hole in the ship's skin, sat down unsteadily. Others dribbled out.

"Crazy man in there!" one of them shouted. "Look out, he's murderous!" The pistols came up. The soldiers began to close in, showing a certain professional eagerness.

They were perhaps within ten feet when a metal plate, sheared off from the pilot's cabin in the fall, lifted up. Barely visible under it was a pair of large, running feet. One soldier, trying to oppose it with his hands, was knocked senseless and bleeding. He might as well have tried to stop an oncoming rocket ship.

Neuro-pistols, bearing from every side, spanged briskly. They partly neutralized one another. Their charges were partly reflected by the metal and partly absorbed by Tolto's great bulk. He was thoroughly confused now. Every way he looked in this glaring wilderness of desert and rocks were enemies.

But there! An opening loomed, cool and dark. The fortress entrance. Tolto dashed into it. There was the sharp challenge of a guard, unanswered; the futile hiss of a weapon.

The improvised shield wedged on a narrowing stairway. Tolto let it stick, ran up alone. The stairway went round and round, climbing ever higher. The fugitive's lungs were bursting.

At last he came to an airlock. He did not know how to operate it, so smashed through. There was no rush of air, because the pressure had already been equalized in the rush to the wreck at ground level. Panting, listening for pursuers, Tolto looked around.

He found himself on a circular roof, bare except for the airlock and a number of upright posts, whitened by the Sun.

It was some moments before he saw the unconscious figure of a man lying on the very edge of the lofty tower on which he was standing—a man naked and blackened. He was lying on his face, one arm and one foot hanging over space as though he had fallen unconscious at the very edge of the abyss.

Tolto collected his excited wits. This, at least was no enemy. His enemies were in power here. This must be a victim, a possible ally.

The man was stirring. The overhanging arm was feebly trying to grasp something. If he were to roll over—

He did not have time. Tolto dragged him in to the safety of the airlock opening, where he could watch.

There were sounds of pursuit, faint and cautious.

Tolto grinned at the naked stranger.

"Who are you, little bug?" he asked.

Sime Hemingway tried to tell him but his swollen tongue would not behave. Instead, he waved in the general direction of the Sun.

Tolto understood. "From Earth? Good guy, prob'ly. Want this dingus?"

Sime was able to take the neuro-pistol. He knew what was expected of him, and strove to collect his faculties so he could obey orders. He crawled a little way into the lock, where he could be in comparative darkness, setting the little focalizer wheel at the side of the pistol for maximum concentration. Such a beam would require good aiming, being narrow, but if it touched a vital center would be infallibly fatal.

Meanwhile Tolto appraised one of the posts on the roof. It was firmly set in masonry, but he found he could loosen it a little by shaking it. Presently he had it uprooted. It made a splendid battering ram, a war club fit for a giant such as he.

"Here they come!" Sime croaked, and, peering around a corner, took careful aim at the foremost attacker. At the first whispering impact of the beam the Martian sprawled, dead.

The soldiers were caught at a disadvantage. They were expecting club or fist, but not the neuro-beam. Nevertheless Sime had no more easy opportunities. The Martians flung themselves down behind the bulge of the curved stairway, and the air became acrid under the malignant neuro-beams.

None of them reached Sime directly, but the stone walls reflected them to some extent, and even under their greatly weakened power he become cold and sick.

The situation was by no means to his liking. There were other weapons to be reckoned with, and he tried to keep consciousness from slipping away from him. When at last his breathing became easier and his diaphragm moved without pain, Sime knew that danger was greatest. For this relief meant that the Martians had withdrawn down the stairway.

"Good-by, boys!" he thought, as he sprinted up into the comparative safety of the open. He motioned to Tolto, who stood hopefully waiting with his great war club, to stand clear.

There it was! Sime saw the faint phosphorescent reflection against the stone where the stairway curved. He did not wait to see the tiny pellet of the atomic bomb floating up, but threw himself flat on the roof, tugging at Tolto, who understood and followed suit.

Even lying prone, and below the edge of the explosion cone, they were nearly blown off the roof. Though no larger than a pinhead, the bomb had the power of a thousand times its weight in fulminate of mercury. When the rain of small stones and dust had subsided, they rubbed their eyes and saw that the airlock was no more. In its place was a shallow pit, ending with the top of the battered stairway.

"Down after 'em!" Sime husked out of a raw throat. "Before they think it's safe to come after us!"

He led the way, the giant after him, carrying his club and a huge rock fragment. Sime saw a cautious peering head, and that Martian died instantly. Then they were around the bend and in the middle of a fight. Sime deflected a hand that held a pistol, and its beam killed another Martian who was about to let Tolto have it at close range.

There was a light-wand affixed to the wall a trifle further down. Tolto waded through the ruck of smaller men, tore it from its socket and hurled it up the stairs. A short sword bit into Sime's shoulder, but there was no force in the stroke, for in that instant Sime paralyzed his enemy's heart with the beam.

An officer barked a command, and the spang of neuro-beams ceased, to be followed by the lethal rustling of swords. The passage was too crowded for the neuro-pistols, giving the outnumbered prisoners the advantage.

Tolto could not swing his club, but he hurled it, like a battering ram, into the middle of twenty or twenty-five of the garrison who were still below him on the steps, trying to get closer. The heavy timber cleared a lane and the two stumbled down over crushed bodies. Sime was now the only one to use his pistol, for he had no friends there to kill accidentally.

The Martians, were putting up a game battle. They were heirs to the traditions and the spirit of Earth's best fighting men. Science had given them deadly and powerful weapons that could kill over long distances, but they preferred to get close to their adversaries.

But Tolto was a Martian too. He had seized a sword from a dying hand and was wielding it with aptitude and power. No formal thrust and parry for him, but merely a savage sweep that sent swords, arms and heads flying indiscriminately.

Sime, following him, his neuro hissing death from side to side, marveled at his ferocity. He saw a bare-bodied, bleeding fighter leap to Tolto's back, his sword poised for a downward stab for the jugular. Kicking viciously at the man who was just then coming at him, Sime tried to bring Tolto's would-be killer down. But Tolto himself attended to him, dashing him to his death with the elbow of his sword arm.

That diversion nearly cost Sime his life. Fortunately for him he tripped, and the sword-thrust that was to disembowel him merely gashed his side. Sime was beginning to enjoy the fight. The exercise was loosening up his cramped muscles, and the shaky feeling due to the reflected beams of the neuro-pistols was leaving him.

Tolto had smashed down the light-wands as they fought their way down the steps, so that now they were in almost complete darkness. One could still see the occasional rise and fall of a glinting sword and the dark shadow of an arm or head. They were almost clear when Tolto received his first serious wound, a stab in the abdomen that let out a sticky stream of blood.

There was an interval of silence, broken only by the groans of the wounded. The air was thick with the odor of raw blood and pungent with ozone. They had fought their way down perhaps two hundred feet of the stairway, and due to its curve they could see neither top nor bottom.

"I'm stuck!" Tolto muttered.

"Bad?" Sime edged to his side, stepping, in the darkness, on the body of the man who had succeeded in delivering that sword-stroke before Tolto's own blade had cleft him. He felt the edges of the wound, but in the darkness could not tell how serious it was.

"Feel sick? Any retching?" he croaked anxiously.

"Tolto's all right," the giant assured him. "I just said I was stuck."

Sime managed to make a hurried bandage out of the slashed fragment of Tolto's blouse, and again they resumed their descent. Strangely, their enemies further up made no move to attack, although there were many left alive.

Sime laid his hand on Tolto's arm.

"Something wrong here. There's somebody at the bottom of the steps, and the fellows above want to give him elbow room. Well, we'll soon see!"

They crawled up a short distance, began to haul inert bodies down, dragging them as far as the last curve, until they had formed a barricade of nineteen or twenty of their late enemies. It was unpleasant work, but justified by following events.

"Can you just see the loom of it?" Sime asked.

"Yes."

"Watch!"

Sime felt about until he found a small fragment broken from the stone steps. Keeping well within the shelter of the convex wall, he crept toward the bend.

"Dig your fingers into a joint and hold on," he instructed Tolto, locating a crack for himself. Then he tossed the fragment gently over the barricade of bodies.

There was the click of its fall, and a moment later things seemed to turn around. Clinging like leeches to the wall, the two men resisted the warped gravitational drag that would have flung them down upon their waiting enemies below. They seemed to be hanging in a well. Sime had a confused impression of piled-up bodies hurtling down—down.

Thereafter everything was normal again, and they were running down the normal steps. Both had swords in their hands now, and within a hundred feet they were upon the "gravitorser" gun. It was a rather cumbersome weapon, comprising a great deal of electrical apparatus, with a D-solenoid surmounting, whose object was to twist the normal lines of gravitation. It was intended for large-scale operations in the open; the few men remaining below had tried a rather risky experiment, for they might have brought the whole fortress down upon them. Now they were untangling themselves from the corpses that had flown at them as iron flies to a magnet.

Sime and Tolto struck them like a tempest. The light was good and the battle short and sweet. Tolto was slowed up a little, but was irresistible, nevertheless. There is nothing surprising about the seeming immunity of a reckless man in battle. He fights by instinct, taking short-cuts that are not as dangerous as they look because the enemy is not expecting them. So Sime and Tolto fought their way down, until there was no one able to oppose them.

Sime pressed a neuro-pistol into Tolto's hand, warned him to sweep the stairs with it, while he coursed around for some of the pellet bombs. He found them, and two of them closed that avenue of attack with a mass of jumbled ruins.

Now they had a breathing spell. A combination of blind luck and foolhardiness had given them temporary possession of this desert outpost. That was their pawn in the game of life and death—the chance to get back and hide among the millions in the cities of the industrial belt. Certain routine precautions had to be taken. They destroyed the radio apparatus, picked a few days supply of food, threw a couple more bombs and made a search for means of transportation: for there was a desert wilderness of four or five hundred miles to be traversed.

They discovered the egg-shaped hull of an enclosed levitator car in the covered courtyard. It was distinguished by the orange and green stripes which are the Martian army standard. Like all army equipment, it was in excellent condition. The hydrogen gages showed a full supply of fuel.

"We're getting the breaks," Sime crowed to Tolto at they surfeited themselves with water before starting. He had covered his nakedness with an ill-fitting fatigue suit.

"Yeh," Tolto agreed, referring to their numerous wounds with sly humor: "lots of 'em."

Nevertheless, they felt pretty happy when the levitator screws took up their melancholy whine. The rocky valley floor dropped away, and the windowless stone walls of the fortress slid down past them. Now they were even with the top.

Through the ports they could see a group of their late adversaries on the roof, standing in strained attitudes. Their immobility was explained a moment later by an electric blue spark from something in the shadow of their bodies.

Instantly Sime, who was at the controls, threw her hard-a-port, dived, looped up. The first explosion of the tiny projectile tossed them up like a monstrous wave, allowed them to drop sickeningly. The exhaust tubes poured out a dense haze as Sime sought for distance. But they were following him. He was five miles away when they finally got the range. The vessel was jarred as if it had hit a rock. One of the atomic pellets had exploded within a few feet of it. There was a dismaying lurch. Sime picked himself up from the floor and dashed to the controls.

"Everything's all right!" he shouted excitedly.

Tolto, however, was listening anxiously. There was a sharp crackling at the stern, where, in a narrow space, the reaction motors provided the forward motive power. In moments of excitement he referred to himself in the third person. He did so now.

"Tolto's afraid that something's wrong! Smells hot, too!"

"Here, take the wheel!" Sime ordered. The explosions of the shells were becoming less dangerous; they were getting too far away.

Sime burned his hand opening the narrow door. The paint was already blistering off it. The trouble was immediately apparent. One of the integrator chambers, in which atomic hydrogen was integrated to form atomic iron and calcium (sometimes called the Michelson effect), had sprung a leak. The heat escaping into the little room was not the comparatively negligible heat of burning hydrogen, but the cosmic energy of matter in creation. Sime slammed the door. The radiated light was so intense that it stung even his hardened skin.

Looking through the rear range-finding periscope, he saw that they were about twenty miles from the fort. They had ceased firing.

"Won't be long, Tolto," he said, taking over the controls himself again, "before our tail's going to drop off. Got to make time."

It was, in fact, about ten minutes when, without warning, their nose dropped.

"Tail's gone!" Sime announced.

Their momentum, under the destructive rate of speed they had been making, was great, and as the levitators, with independent power supply, still held them up, Sime continued to steer a course for the twin cities of Tarog. He was aided by a light breeze, and the Sun was nearing the western horizon by the time their rate of motion had become negligible.

"Might at well land," Sime decided. "Conserve fuel. If we get a favorable wind to-morrow we can go up and drift with it."

But Tolto, who had been narrowly scanning the terrain, advised continuing a little longer.

"I thought I saw a little smoke, a few miles ahead. Seems to be gone now. But we're still drifting slow."

Sime searched the indicated spot in the ground glass of the forward magnifying periscope. After a few minutes he discovered a blackened spot which might be the remains of a fire. It was surrounded by huge blocks of orange rock, the igneous rock which is the outstanding feature of the Martian desert landscape.

"Looks like he built the fire around there so nobody on the same level would see him," he hazarded. He set the altitude control to fifty feet. There was part of the globular skeleton of a desert hog in the fire; whoever had built it had dined most satisfyingly not long before, and as the fugitives looked their stomachs contracted painfully.

"I could eat a whole one of them myself," Tolto said wistfully.

The urge to descend here was strong upon Sime too. He realized that the fire might have been made by some dangerous criminal—a fugitive from justice; but dangerous men are no novelty to the I. F. P. On the other hand, there was a possibility that it was just some political offender, driven into the desert by persecution. Or a prospector. At any rate, he would have food, or would know where it could be procured.

They had drifted some hundreds of yards farther and the ground was getting constantly more broken, so the best time to land was as soon as possible. Slowly the little ship settled, scraped on a rock and arrested its slight forward motion, crunching solidly in the stony soil.

"Take a neuro, Tolto," Sime advised. "Whoever's here, if he or they are dangerous, we won't get close enough to touch 'em with a sword."

Tolto took the weapon without a word. They locked the door of the ship. Men have been marooned for neglecting that little precaution.

They walked in a spiral course, making an ever-widening circle, looking sharply from left to right. Presently they came to the remains of the fire. The ashes were hotter than the ground, proving that they had been recently made.

But nowhere was there any sign of men. They shouted, but only weird echoes answered.

The ship was now out of sight, and solitude pressed upon them. They felt an uneasy desire to get within comfortable constricting walls.

They found the ship without difficulty.

"Well, whoever it was has lammed," Sime concluded. "Tolto, you climb on top of that rock. Watch me. If you see anybody after me, let 'em have it. I'm going to see if I can scare up a desert hog somewhere."

Neither had stirred from his place, however, before they were suddenly stricken to the ground. They felt the familiar sensation of cold and suffocation—the paralysis caused by a diffused beam from a neuro-pistol. Tolto was a little slower to fall, but he only lasted a second longer. They knew that someone was taking the weapons out of their helpless hands. Then life returned.

"Get up," said a languid voice back of them, "and let's have a look at the looks of ye."