Dawn broke over the tangled jungles of Tara, followed by the bright sun of Alpha Centauri rising out of the eastern sea and slowly climbing higher and higher. In the dense unexplored wilderness, living things, terrible things, opened their eyes and resumed their never-ending quest for food. Once again Alpha Centauri had summoned one hemisphere of its satellite planet to life.

Meanwhile, high in the heavens above Tara, six Earthmen blasted into the flaming brilliance of the sun star. Using delicate instruments instead of claws, and their intelligence instead of blind hunger, they prepared to do battle with the sun star and force it to release the precious copper satellite from its deadly, consuming grasp.

The crew of the Polaris assembled on the control deck of the great spaceship, and facing their commanding officer, waited patiently for the word that would send them hurtling out to their target.

"The jet boats are all ready, sir," reported Tom. "We're dead ship in orbit around Junior at an altitude of about three hundred miles."

"Does that mean we're falling into the sun too?" gasped Shinny.

"It sure does, Mr. Shinny," said Alfie, "at more than twenty miles per second."

"The jet boats have enough power to get back from Junior to the Polaris, Mr. Shinny," reassured Tom. "And then the Polaris can blast off from here. The jet boats wouldn't go much higher off Junior this close to the sun."

"But if we go beyond the two-hour limit, the Polaris can't blast off either," commented Roger dryly.

"All right. Is everything set?" asked Connel. "Astro, is the reactant loaded?"

"No, sir," said Astro, "but it's all ready to go in."

"Good!" said Connel. "Now we all know how important—and how dangerous—this operation is. I don't have to tell you again. You stay here on the control deck, Tom, and keep in touch with us on Junior at all times. You know what to do?"

"Yes, sir," replied Tom. "I'm to stand by and give you a minute-by-minute warning check until final blast-off time."

"Right," said Connel. "And remember, we're counting on you to tell us when to blast off. We'll be too busy down there to pay any attention."

"I understand, sir," replied Tom. His face was passive. He was well aware of the responsibility.

"Very well," said Connel finally, "the rest of you board your jet boats! This is going to be the hottest ride we'll ever take, and I don't want it to get any hotter!"

Silently, their faces grim masks, the five spacemen filed out of the control room, leaving Tom alone. Presently he heard the cough of the rockets in the jet boats as one by one the small space craft blasted out of the Polaris. Suddenly Tom began to shake as he realized the importance of his task—the responsibility of counting time for five men, time that could cost them their lives. If he made a single mistake, miscounted by a minute, the expedition to Junior would end not only in failure, but in tragedy.

As quickly as the thought came, Tom pushed it aside and turned to the control board. No time now for fear. Now, more than any other time in his life, he had to keep himself alert and ready for every emergency. As a child he had often dreamed of the day when, as a spaceman, he would be faced with an emergency only he could handle. And in the dreams he had come through with flying colors. But now that it was a reality, Tom felt nothing but cold sweat breaking out on his forehead.

He turned his whole attention to the great solar clock overhead. Time had already begun slipping away. Ten minutes of the two hours had swept past. They must be on Junior by now, he thought, and flipped on the teleceiver. He focused on the satellite's surface. There in front of him were the three jet boats. Major Connel, Roger, Astro, Alfie, and Mr. Shinny were so close that Tom felt as though he could touch them. They were unloading the first reactor unit, with Astro and Shinny digging the hole. Tom glanced at the clock, turned to the microphone, and announced clearly:

"Attention! Attention! Corbett to Connel. One hour and forty-eight minutes until blast-off time—one hour and forty-eight minutes to blast-off."

He flipped the switch and watched the screen with rising excitement. The crew on the satellite had completed the installation of the first reactor unit. He saw them blasting off in their jet boats for the second spot. He adjusted the teleceiver and tried to follow them, but they disappeared. He glanced at the clock.

"Attention! Attention! Corbett to Connel. One hour and forty-seven minutes to blast-off—one hour and forty-seven minutes to blast-off."

On the satellite, in the deep shadow of a protecting cliff, each of the five Earthmen paused involuntarily when they heard Tom's warning.

"Forget about the time!" snapped Connel. "By the blessed rings of Saturn, we'll finish this job if it's the last thing we do!"

Connel went to each of the working figures and adjusted the valve, regulating the air-cooling humidity control on their space suits. "Getting pretty hot, eh, boys?" he joked, as he stopped one and then the other to make the delicate adjustment counteracting the heat that was increasing each second they remained on the satellite.

"How hot do you think it is, sir?" asked Roger.

"Never mind the heat," said Connel. "These suits were designed to withstand the temperature of the light side of Mercury! It gets boiling there, so I guess we can stand it here for a while."

One by one, Alfie, Shinny, Roger, and Astro completed their assigned roles, digging the holes, placing the reactors inside, setting the fuse, covering it up, then quickly gathering the equipment, piling back into the three jet boats, and heading for the next point. Landing, they would tumble out of the small space craft almost before the rocket had stopped firing and begin their frantic digging in the hard surface.

[180]

Over and over, they heard Tom's crisp clear count of time. Five minutes passed, then ten, and before they knew it, a full half-hour of the precious time had vanished. They completed the installation of the second unit and climbed back into the jet boats. The first two units had been buried at points protected from the sun by cliffs, and they had been sheltered from the burning rays.

But, approaching the position for the third reactor unit, Connel searched in vain for some shade. He wasted five precious minutes, scouting an area of several miles, but he could find nothing to protect them on the flat plain.

"Better put in the ultraviolet glass shields in our helmets, boys," he called into the jet-boat communicator. "It's going to be mighty hot, and dangerous."

"Aye, aye, sir," came the replies from the other two jet boats soaring close by.

Roger began refitting their space helmets with the dark glass that would shield them from the strong rays of the enlarging sun.

"Ever been outside in the direct path of the sun with no protection, Roger?" asked Astro.

"No," replied Roger. "Have you?"

"Once," said Astro softly. "On the second moon of Mars, Phobos. I was bucking rockets on the old chemical burners. I was on a freighter called the Happy Spaceman. A tube blew on us. Luckily we were close enough to Phobos to make a touchdown, or the leak would have reached the main fuel tanks and blown us clean out to another galaxy."

"What happened?" asked Roger.

"I had to go outside," said Astro. "I was junior rocketman in the crew, so naturally I had to do all the dirty work."

Tom's warning call from the Polaris control deck, tuned to the open communicators of all the jet boats, broke through the loud-speaker.

"Attention! Attention! Corbett to Connel. One hour and twenty minutes to blast-off time. One hour and twenty minutes to blast-off time."

The two cadets looked at each other as they heard Tom's voice, but neither spoke. Finally Roger asked, "What happened on Phobos?"

"No one bothered to tell me," continued Astro, "that I had to protect myself from the ultraviolet rays of the sun, since Phobos didn't have an atmosphere. It was one of my first hops into space and I didn't know too much. I went outside and began working on the tube. I did the job all right, but for three weeks after, my face was swollen and I couldn't open my eyes. I almost went blind."

Roger grunted and continued to line the clear plastic fish-bowl helmets with the darker protective shields.

Connel's voice rang through the cabin over the communicator: "I guess we'd better go down and get it over with. I don't see anything that will give us any protection down there. Be sure your humidity control is turned up all the way. As soon as you step outside the jet boat, you're going to be hit by a temperature of four hundred degrees!"

"Aye, aye, sir," came Shinny's reply over the intercom. Roger flipped the communicator on and acknowledged the order.

Astro and Shinny followed Connel's jet boat in a long sweeping dive to the surface of the satellite. Stepping out of the air-cooled jet boat onto the torrid unprotected surface of the flat plain was like stepping into a furnace. Even with space suits as protection, the five Earthmen were forced to work in relays in the digging of the hole for the reactor unit.

"Attention! Attention! Corbett to Connel. One hour exactly to blast-off time! One hour—sixty minutes—to blast-off time."

Tom flicked the teleceiver microphone off, and on the teleceiver screen, watched his spacemates work under the broiling sun. They were ahead of time. One hour to complete two more units. Tom allowed himself a sigh of hope and relief. They could still snatch the copper satellite from the powerful pull of the sun.

Suddenly Tom heard a sound behind him and whirled around. His eyes bulged in horror.

"Loring!" he gasped.

"Take your hand off that microphone, Corbett," snarled Loring, "or I'll freeze you!"

"How—how did you get out?" Tom stammered.

"Your buddy, Manning," sneered Loring with a short laugh, "decided he wanted to paste my ears back. So I let him. He was so anxious to make me lose a few teeth that he didn't notice the spoon I kept!"

"Spoon?" asked Tom incredulously.

"Yeah," said Mason, stepping through the door, a paralo-ray gun leveled at Tom. "A few teeth for a spoon. A good trade. We waited for your pals to leave the ship, and then I short-circuited the electronic lock on the brig."

Tom stared at the two men unbelievingly.

"All right, Corbett, get over there to that control board," growled Loring, waving the paralo-ray gun at Tom. "We're going back to Tara."

"Tara?" exclaimed Tom. "But Major Connel and the others—they're—they're down on the satellite. If I don't pick them up, they'll fall into the sun!"

"Well, ain't that too bad," sneered Loring. "Listen to that, Mason. If we don't hang around and pick them up, they'll fall into the sun!"

Mason laughed harshly and advanced toward Tom. "I only got one regret, Corbett. That I can't stay around to see Connel and the Manning punk fry! Now get this wagon outta here, and get it out quick!"