celleration dragged them
back. Across the cabin Tawney sprawled on the floor. The stunner flew
from his hand and crashed against the rear bulkhead.

On the panel Greg could see the accelleration gauge climbing
swiftly ... past four g's, up to five, to six. The ship was moving
wildly; there was no pilot, no course.

With all the strength he could muster Greg tightened his arm on the
shock bar, lifting his other arm slowly toward the cut-off switch. He
had spent many hours in the accelleration centrifuge at Star-Jump,
learning to withstand and handle the enormous forces of accelleration
for brief periods, but the needle was still climbing and he knew he
could not hold on long. His fingers touched the control panel. He
strained, inching them up toward the switch....

His fingers closed on the stud, and he pulled. The engine roar ceased.
On the floor behind him Tawney moved sluggishly, trying to sit up. Blood
was dripping from his nose. He was still too stunned to know what had
happened.

Greg leaped across the room, caught up the stunner, and then sank to the
floor panting. "All right," he said as his breath came back, "that's
all. Your ship may have trouble finding us now ... but I bet our pilot
can get us back to Mars."

* * * * *

When they left the Sun Lake City infirmary it was almost noon, and the
red sun was gleaming down from overhead. Walking slowly, the Hunter
twins moved along the surface street toward the U.N. building.

"He'll recover without any trouble," the doctor had assured them. "He
caught the stunner beam in the shoulder, and it will be a while before
he can use it, but Johnny Coombs will be hard to keep down."

They had promised Johnny to return later. They had had check-ups
themselves. Both Tom's eyes were surrounded by purple splotches, and his
broken left arm was in a sling. Greg's arms and legs were so stiff he
could hardly move them. The Major and the Lieutenant had been sore but
uninjured.

Now the boys walked without talking. Already a U.N. linguist was at work
on the record tapes from the metal cylinder, and a mathematician was
doing a preliminary survey on the math symbols on the metal block.

"I hope there's no trouble reading them," Greg said.

"There won't be. It'll take time, but the records are decipherable. And
Dr. Raymond was certain that the engineering can be figured out. Earth
is going to get her star-ship, all right."

"And we've got wor