It was all right to spend your time poking around with bottles and test tubes if you couldn't do anything else, but it took something special to pilot an XP ship for Project Star-Jump. And after this run was over, even Tom would have to admit it....

There was a lurch, and quite suddenly the enormous pressure was gone.

Something was wrong. He hadn't pushed the cut-off button, yet the ship's engines were suddenly silent. He jabbed at the power switch. Nothing happened. Then the side-jets sputted, and he was slammed sideways into the cot.

He snapped on the radio speaker. "Control ... can you hear me? Something's gone wrong out here...."

"Nothing's wrong," the captain's voice said in his earphones. "Just sit tight. I'm bringing you back in. There's a call here from Sun Lake City. They want you down there in a hurry. We'll have to scratch you on this run."

"_Who_ wants me down there?"

"The U.N. Council office. Signed by Major Briarton himself and I can't argue with the Major. We're bringing you in."

Greg Hunter sank back, disappointment so thick he could taste it in his mouth. Sun Lake City! That meant two days at least, one down, one back, maybe more if connections weren't right. It meant that the captain would send Morton or one of the others out in his place. It meant....

Suddenly he thought of what else it meant, and a chill ran up his back.

There was only one reason Major Briarton would call him in like this. Something had happened to Dad.

Greg leaned back in the cot, suddenly tense, as a thousand frightful possibilities flooded his mind. It could only mean that Dad was in some kind of trouble.

And if anything had happened to Dad....

* * * * *

The sun was sinking rapidly toward the horizon when the city finally came into sight in the distance, but try as he would, Tom Hunter could not urge more than thirty-five miles an hour from the huge lurching vehicle he was driving.

On an open paved highway the big pillow-wheeled Sloppy Joe would do sixty in a breeze, but this desert route was far from a paved road. Inside the pressurized passenger cab, Tom gripped the shock-bars with one arm and the other leg, and jammed the accelerator to the floor. The engine coughed, but thirty-five was all it would do.

Through the windshield Tom could see the endless rolling dunes of the Martian desert stretching to the horizon on every side. They called Mars the Red Planet, but it was not red when you were close to it. There were multitudes of colors here ... yellow, orange, brown, gray, occasional patches of gray-green ... all shifting and changing in the fading sunlight. Off to the right were the worn-down peaks of the Mesabi II, one of the long, low mountain ranges of almost pure iron ore that helped give the planet its dull red appearance from outer space. And behind him, near the horizon, the tiny sun glowed orange out of a blue-black sky.

Tom fought the wheel as the Sloppy Joe jounced across a dry creek bed, and swore softly to himself.