"They opened the control banks and threw a few shunts across the relays. Then they ran one cable to the hypos. But so far as I can see, what they did shouldn't make any great difference in the operation of the ship." He stared at Gary dubiously, "You don't think the old man's giving us the runaround, do you? Pretending to put out, when really all he's doing is stealing the secret of Earth's hypatomic?"

Lark O'Day, from the neighboring plot desk, looked up, glowering darkly. "Mac," he advised, "if I thought you really meant that, I'd come over there and push your face so far down your throat you'd have a tapeworm's view of your own stomach. Anybody who cracks about Dr. Kang—"

"Also cracks," grinned Gary, "about Kang's charming daughter, Pen-N'hi. Which Lark doesn't allow. But, no, Mac; I'm sure you're mistaken. As soon as we reach the asteroid belt Dr. Kang has promised us proof that the force-shield has been installed and is in operation."

With this assurance everyone had to be content, until ten days out from Mars the Liberty hove within range of that tremendous swarm of shuttling bodies which comprises the Bog, spaceman's term for the belt of myriad asteroids ranging in size from tiny granules of rock to life-sustaining mountains of matter larger than many satellites.


It was when they reached this point that Dr. Kang offered his promised proof. As the leaders of the party gathered within the Liberty's control turret he said, "And now, for those of you who have not had the opportunity of seeing the Martian force-shield operate, a little demonstration may be heartening. Who's at the controls? O'Day? Good! Larkspur, my friend ... you see that asteroid moving within our vision range to loft and starboard?"

O'Day, fingers flickering incessantly over the keyboard as the ship wove its way through the treacherous belt, nodded tightly.

"I see it," he grunted, "and I'm getting out of its way now. If that thing ever plowed into us, the Liberty would be one small blob of crumpled metal floating through space."

"On the contrary," said Dr. Kang smoothly, "you will make no attempt to avoid the planetoid. You will set a course directly for it."

"Directly—!" gulped Lark.