"Vroom-m-m!"

As the shattering blast of noise pounded against his eardrums, Tom Corbett opened his eyes, blinked, and stared around him. By the dim light from a small window in the wall over his head, he saw that he was in some sort of metal enclosure. Suddenly the floor trembled and again the shocking, shattering noises rang through his aching head. He tried to sit up but found that his hands were tied behind his back. The ropes were so tight, his hands were almost completely numb. Slowly he clenched his fingers, then opened them again, repeating the process over and over again while needlelike pains shot through his hands. Finally there was feeling in his fingers again and he struggled to a sitting position.

Again the metal enclosure vibrated and there was another thunderous blast. This time Tom recognized the sound.

"A jet!" exclaimed the cadet aloud. "I'm in the van of a jet truck."

When Tom tried to stand up, he found that his feet were bound. Again he went through the slow, painful process of restoring circulation in his legs and feet, gritting his teeth against the needles of pain. Finally he felt strong enough to push his back against the wall and inch his way upright.

The noise around him continued. Again and again, he could hear the shattering explosions of the exhausts and the screaming whine of the jets. Looking around carefully for the first time, he saw that the van was empty except for a pile of heavy quilted rugs in one corner which he knew were used to protect and cushion cargo.

Hopping to the corner, he flopped down on the blankets and, one by one, he began dragging them out. There was nothing else in the van that would aid him in cutting the thick ropes around his wrists and he hoped to find something under the heap.

Suddenly he felt something hard and boxlike under the last blanket and he tore it off quickly.

He nearly screamed for joy when he recognized a heavy metal toolbox. Sitting on the floor of the van, he maneuvered the top open, then spun around and hopefully looked inside. There was nothing in the box but a dirty cloth, and Tom slumped back in bitter disappointment.

Suddenly the cadet became aware of the intense heat inside the van. He was sweating, and he found it difficult to breath. He inched over to the side of the huge truck and touched the metal paneling. It was blisteringly hot.

"The New Sahara," he thought, a vision of the desolate sun-baked wasteland of the Martian desert flashing through his mind.

He looked around again desperately. The only thing in the van that might cut through the rope was the edge of the toolbox. He inched his way back to the box and began rubbing the rope across the edge of the box, but it was too smooth.

Tom knew that he would have to roughen the edge of the box, so that it would cut the thick fibers of the rope, and in sudden inspiration, he inspected the floor of the van. The heavy-gauge metal was scarred and roughened from the many heavy loads dragged across it. He turned the box over, and with great difficulty, rubbed it back and forth across the floor. Every few minutes he tested the edge of the box with his finger. It was losing its slick surface, but there was a long way to go.

It got hotter inside the van and Tom's uniform was soaked with sweat. He found it difficult to breathe and the continuous roar of the jets tortured his ears.

He did not know how long he had worked, but eventually, he felt that the edge of the box was sufficiently rough to try to cut the ropes. He righted the box, placed the ropes on the edge again and, with a silent prayer, began scraping them across the metal.

After a few minutes there was a tug at the bonds. The cadet pushed harder. There was another tug and the rope seemed to give a little. Working frantically, he sawed back and forth. The sweat poured from his forehead, his arms and back ached unbearably, and soon he felt something warm and wet begin to trickle down the palms of his hands. He knew it was blood, but he kept on grimly, and suddenly he was rewarded. With a snap, the ropes parted. His hands were free!

Tom hastily untied his feet, and giving the toolbox an affectionate pat, rose to his feet to begin the next step in his plan to escape.

The young cadet examined the entire surface of the inside paneling of the van with his finger tips. He could find no opening other than the back door, which he knew was locked by an electronic beam. Without the proper light-key adjustment, the door could not be opened. And the vent high in the wall was much too small to help him.

He sat down, disheartened. He was still no better off than before. And there was no way of telling where he was, whether it was day or night, and how long he had been riding in the jet truck.

He rested on the floor of the van, the bumpy ride cushioned by the soft blankets, and tried to recall the events that had led him into this trap. He remembered the two men, Cag and Monty, and grimly vowed to repay them if he ever met them again.

Suddenly remembering something more immediate, Tom sat bolt upright. He got up and went to the front of the huge van. There he knelt down in one corner and felt the floor with his hands. He found exactly what he had been hoping for. A large grate, and it was cool! He jumped up, grinning, grabbed the heavy toolbox and carried it back to the corner where he let it drop on the grate. It sagged slightly, near the corner. He picked up the box and dropped it again. The grate sagged a little more. Tom got down on his knees and felt along the edge of the floor. The grate was giving way.

He really began to hammer in earnest then. And each time the heavy box thudded on the grate, he thanked his lucky stars that he had lived near a garage when he was a boy back in New Chicago. Time and time again, he had slipped inside the huge vans after the produce had been taken out, to find a piece of fruit. He had gotten into the sealed vans, through the refrigerating compartment, a huge unit beneath the van and connected to the cab. Opening the outside hatch to the unit, he had squeezed inside and then unscrewed the grate from the bottom.

With a final hard smash, the grate gave way, clattering into the recesses of the refrigerating unit. Now Tom was grateful for the roar of the jets. It covered the sound of his escape.

Quickly reaching down into the unit, Tom began tearing the mechanism apart; ripping out coils of copper tubing and rubber connections. Disconnecting a pipe, he used it to pry apart the rest of the unit, and finally, after removing the broken parts, there was room enough for his body.

Stuffing the heavy pipe in his tunic, Tom dropped into the unit and opened the outside hatch. A blast of cool air struck him. The sun was setting and the cadet knew that soon the near-zero temperatures of night would settle over the desert. Tom poked his head out and the air stream hit him like a solid wall. He looked back past the spinning wheels and saw a long stretch of deserted road bordering a canal. His view forward was blocked by the overhanging cab of the truck. The small step up to the cab was a foot away. Tom eased back into the compartment again and sat back against the wall to consider his next move. He would have a better chance of not being seen if he waited for darkness. On the other hand, they might reach their destination before that and he would be caught. Tom made up his mind quickly.

Moving back to the hatch, he eased himself through the opening. There was a ticklish moment when he had to let go of the side of the compartment and swing over on the step. He took a deep breath and lurched forward.