torpedoes into the launching tubes and bring up a new pair in reserve. With that much done, he closed the hatch and climbed down the ladder.

In the control room, he found Donna and Truesdale peering into the screen. He crowded close to look over their shoulders. A small blob of light floated near the center of the view. "That it?" he asked.

"Yes," answered Donna. "Just enough Mars-light to show it."

"How near are we?" asked Phillips.

"About a hundred and fifty miles. I have quite a large magnification, but they may spot us if they're alert. Are you ready to ... do something?"

"Reasonably," said Phillips. "Where's Brecken?"

"You probably killed him!" Truesdale broke in accusingly.

"I found a first-aid kit and gave him a shot," said Donna. "He has a nasty lump on the head, but he might sleep it off."

Phillips was watching Truesdale. The youth was visibly nervous. Was it the thought of Brecken, the engineer wondered, or fear of what they were planning to do? Perhaps it would be best to clear the air now, before it was too late.

"I guess you can handle it here, Donna," he said. "Truesdale and I will go to the turret and stand by."

The youth shrank away. "No! I won't go up there again! You can't make me do this!"

"Do what?" demanded Phillips.

"It's murder! You both know it is! They won't even have any warning."

"I hope not," said Phillips drily. "They might get us!"

"You would put it that way," sneered Truesdale; "you're homicidal at heart anyway!" He turned on Donna, wiping perspiration from his forehead. "Are you going to let him do it?" he shrilled. "Are you going to help him commit such a crime?"

The girl stared at him with a worried look in her blue eyes but said nothing.

"Come on, Truesdale," said Phillips, making an effort at a peaceful, persuasive tone. "It will be either their lives or ours if they spot us—and millions more if they get by. They'll be too desperate to think of us. Do you want to die?"

The instant he spoke the last words, he remembered the other's record and wished he had kept quiet. He saw, a strange, wild expression creep over Truesdale's features. It changed into a look of hateful cunning as the youth, began to sidle toward the door.

"I'm not afraid to die!" he boasted in a low-pitched but tense voice. "But how about you, Phillips? How about the big, brutal space engineer who is proud of smashing men's skulls against steel walls, who would like nothing better than to blow up a shipload of innocent people. How do you really know they're dangerous? But you don't care, do you?"

"Truesdale!" snapped Phillips. "Calm down!"

"I'll calm you down with me!" shouted the other hysterically. "I'll show you who's afraid to die!"

He ducked through the door toward which he had been backing. Phillips lunged after him, just barely missing a grip.

"On your toes!" he shouted over his shoulder to Donna, and turned on all jets.

But Truesdale, driven by his peculiar fury, not only stayed ahead as they raced along the corridor, but actually gained.

He was fifteen or twenty feet out in front as they reached the midway point. Phillips, expecting him to take refuge in the rocket room, was completely fooled when Truesdale leaped for the ladder in the vertical well. He stumbled, and grabbed a handrail to stop himself. The other was swarming upward. Phillips sprang to follow.

Hardly had he climbed half a dozen rungs, however, than he saw he was outdistanced. Truesdale's feet were already disappearing beyond the hatchway. Phillips waited for the airtight door to slam shut. It remained open....

Then a thrill of instinctive fear shot through him as he thought of what Truesdale might do—probably was doing at that very instant!

Throwing his feet clear of the rungs, he plunged back toward the deck, guided only by his hands brushing the sides of the ladder. As Phillips reached the junction of the passages, he kicked desperately away from the ladder. He landed with a thump that would have hurt had he been in a calmer state.

Rolling over toward the control room, he came to his feet in time to glimpse Donna looking out the doorway before a jarring shock floored him again.

The deafening roar of an explosion resounded in the corridor as a brilliant light was luridly reflected from somewhere behind him. The bewildering force hurled him at the deck; he saw he could not prevent his head from striking—

Phillips found himself on hands and knees, staring stupidly at the deck a few inches past his nose. As in a nightmare, he seemed to spend an eternity pushing himself painfully to his feet. Clutching a handrail, he finally made it.

He saw Donna kneeling in the doorway, hand to head. As he watched, the girl looked at her hand, and dazedly pulled out a handkerchief to wipe off the blood.

Then Phillips became aware of a high breeze in his face. Behind him, the sound of rushing air rose to a moan, then to a shriek. That shocked him to his senses.

"Button up!" he screamed above the noise, bringing his hands together in an urgent gesture understood by all spacemen.

As the girl staggered to her feet, he whirled and leaped toward the junction of the cross corridors. He wasted no time in a vain glance upwards—he knew what Truesdale had done. Only setting off the torpedoes' rockets in the enclosed turret compartment would have caused an explosion just severe enough to rupture the ship's skin; if the warheads had gone off, he never would have known it.

Diving headlong through the opening in the deck, he experienced a dizzying shift of gravity as he passed through the plane of the main deck. When he had his bearings again, he scrambled "up" the ladder toward the belly turret. By the time he got the airtight hatch open, he was beginning to pant in the thinning air. He pulled himself through at last, and sealed the compartment.

Phillips sucked in a deep, luxurious breath while he glanced about. This turret, he saw, was a duplicate of the other. He immediately located the intercom screen and called the control room. Donna's worried face appeared. "Where are you?" was her relieved inquiry.

Phillips explained what had happened. "The only thing," he concluded, "is to try it from here."

"I think they must have spotted the flash," Donna told him. "The instruments show a shift in their course."

"Blast right at them!" said Phillips. "We might get away with it if we're quick."

He turned away, leaving the intercom on. A few quick steps took him to the control panels in the bulkhead. Guided by his lessons in the other turret, and by faded memories of space school on Earth, he brought up two of the torpedoes. He checked the radio controls and ran the missiles into their launching tubes. As he worked, with nervous sweat running down into his eyes, he was aware of the intermittent jar of rocket blasts.

"Run 'em down!" he muttered, trying to steady his hand on the controls.

He had a hand at each panel, with the torpedoes poised viciously in the tubes, when he heard Donna's shout, shrill with excitement, over the intercom.

Instantly, he launched the missiles. He started the rockets by remote control, and scanned the screens for a sight of the other vessel.

For a moment, his view was confused by the expanding puff of air; then that froze, and drifted back to the hull, and he could see the stars.

Donna's voice, strained but coldly controlled, came over the intercom with readings from her instruments. He corrected his courses accordingly.

Then he saw the image of their target