later. Meanwhile we've got to pass the time, stay as well as we can, and keep our heads on straight."

Sure—straight! If Brinker hadn't turned foolish before they had come, they wouldn't be out here at all. In a month they were already thinning down from malnutrition and strain. At first, thinking coldly, Copeland was sure they'd wilt and die long before they got near the Moon.

Then, as they managed to steady themselves some by the diversions of playing cards, and studying the intricacies of Martian equipment, he began to fear once more that Brinker might succeed in his efforts—but fail terribly in result.

Many times Copeland went over the same arguments, struggling to speak calmly, and without anger: "I wonder if you realize it, Brinker—with enough velocity one large meteor carries more energy than a fission bomb. A whole comet would affect thousands of square miles of the lunar surface, at least. Smash equipment, kill men. And if the comet happened to miss the Moon and hit Earth—"

Sometimes Brinker's expression became almost fearful, as at an enormity. But then he'd turn stubborn and grin. "There's plenty of room to avoid hitting the Earth," he'd say. "On the Moon, astronomers will warn of the shifted orbit of Brulow's Comet in plenty of time for everybody to get out of danger. Most of what we've got to worry about now, is our lives, or jail ..."

A moment later, as like as not, they'd be slamming at each other with fists. Copeland found it hard to contain his fury for the man who had brought him such trouble, and—without intent—was so determined to extend it to many others.

Brinker kept winning the scraps. But Copeland's ten-year age-advantage meant something when it came to enduring hardship and partial-starvation over a long period. They didn't weaken equally.

This levelling of forces was one thing that Copeland waited for. Another was that when Brulow's Comet was found to be off course, a ship might be sent to investigate. He never mentioned it, certainly; but once Brinker said: "I'm ready for what you're thinking, Cope. I've got weapons."

By then they spent much of their time in torpid sleep.

Another difficulty was that it was getting harder to keep one's mind consistently on the same track. Space, tribulation, and the months, were having their blurring effect.

Often, Copeland spent many hours in wistful reverie about his girl, Frances, in Iowa. Sometimes he hated all people—on Earth, Moon, and everyhere, and didn't care what happened to them. On other occasions Brinker's basic desire to lessen the desolation of the lunar scene looked supremely good to him—as of course it always had, in principle. Then, briefly and perhaps madly, he was Brinker's pal, instead of yearning to beat him to a pulp.

His victory, now, was almost easy. Then all he had to do was wait to be picked up; the ship was coming nearer. Through the now much-brightened glow of the comet, it had ceased to be a planetlike speck reflecting sunlight; and showed its actual form.

Confusion whirled in Copeland's head; hunger gnawed in him. Yet he looked down at Brinker—poor Brinker, beaten unconscious inside his spacesuit. Brinker had tried to fight lifeless dreariness. Copeland, weak of body and fogged of mind, was now close to maudlin tears. Dreariness was the enemy—here as elsewhere. He tried to think; his stubborn nature mixed itself with splinters of reason, and seemed to make sense.

His twenty months of suffering out here had to be used—mean something—didn't it? It couldn't be just a futile blank. You had to follow a thing started through to the end, didn't you? Brinker wanted to improve the Moon, which certainly needed that. Okay—finish the job that had gone so far. Damn desolation everywhere! Fight it! Smash it! Sudden rage made Copeland's thin blood pound. Dimly he realized that he was driven by the same dreariness-disease that motivated Brinker. So what? Who cared about smashed lunar equipment, after all. And beside experience, prison would be paradise.

Copeland fired a Martian rocket-launcher, aiming behind the ship. He saw the blaze of atomic fission. Jets flaming, the craft fled.

In his phones he heard a voice that he remembered: "That you, Brinker? Trying your father's trick, eh? Idiot! You'll kill yourself, or be executed. And now you even shoot!"

Fury at Krell clinched Copeland's decision. He did not answer him. But when Brinker woke up he said savagely, without friendship or forgiveness, yet with cooperation: "We're on the same side, now. Let's aim Brulow's Comet."

Concentrating was hard, but they had their instruments and calculators. Velocity, position, and course of both comet and Moon had to be coordinated to make them arrive in the same place at the same moment. It was a problem in astrogation, but a comet was not as easily directed as a space ship. Copeland had once thought that the necessary fine guiding couldn't be done. The jet-system they had rigged in that inconveniently whirling nucleus was crude.

But one thing was in their favor; they had ample time. They could adjust their course with the jets, check with instruments, and re-adjust—again and again. Copeland found himself doing the vital part of the job; he was better at math than Brinker.

They still had plenty of Martian food left—for what it was worth to human insides. Perhaps unified purpose and action brightened their outlook a little, helping their bodies. They could never work very long—even in the almost total absence of gravity. But—at least—their weakness wasn't increasing now.

During those last four months they drove several ships away. Earth and Moon swelled to spheres, ahead. Brulow's Comet lengthened its tail under increased solar light-pressure. Intensified radiation made its shifting colors glorious.

Brinker and Copeland lined their gigantic missile up on its target as perfectly as they could. Fifty hours before the crash was due, they smashed most of the jets. The remaining ones they tried, feebly, to refit into their ship, meaning thus to escape.

More missiles were fired carefully—not to do damage, but to discourage the intruders; the latter were held at bay for another twelve hours. Copeland and Brinker left radio commands and threats unanswered, so it was hard for their opponents to get a fix on their position in the whirling nucleus.

Explosions blazed around them, but never very close. Masses of iron and stone were shattered and half vaporized, cooling subsequently to fine dust. The nucleus of Brulow's Comet expanded a bit under the battering that went on within it.

At an opportune moment, Copeland and Brinker clung to one of their jet-tubes and, gunning it very lightly, rode it from the central core-mass of the nucleus to a lesser meteor, and hid in a cleft. A dust-poll had concealed their change of position. And now, with so many other large meteors around them, they would be almost impossible to find.

They glimpsed the Patrol craft invading the heart of the comet. Men poured forth, struggling to set up jets in the hope of still deflecting this juggernaut from the Moon. But the comet was already much too close; before the setting-up was