He told of what had befallen him in the Rogan power-house. "That lever, Dex!" he said swiftly. "It's the keynote of the whole business. It absolutely controls the pull of gravity, and Lord knows what else besides. If we could only get at it again! Perhaps we could not only shut it off so that Jupiter's pull would function again, but also reverse the process so its gravity would be _increased_! Think what that would mean! Every Rogan in the red empire stretched out and immovable, possibly crushed in by his own weight!" "It's a wonderful thought," sighed Dex; while Greca's eyes glowed with a sudden hope for her enslaved race, "but I don't see how we could ever--" He stopped; and glanced in alarm down the passage behind them. Greca and Brand, hearing the same soft noise, whirled to look, too. * * * * * Far down the passage, just sneaking around the bend, was a group of Rogan guards, each armed with a death-tube. "Back to the pen!" cried Brand. He slid the bolt, and jerked the door open. They rushed into the walled enclosure again, the slamming of the door behind them cutting off the enraged squeals of the Rogans. "This isn't going to mean anything but a short delay, I'm afraid," said Brand, clenching his fists in an agony of futility. "They'll be in here in a minute, and get us like trapped rats." "Not before we get a lot of them," said Dex grimly. "But that isn't enough, man! We don't want to die, no matter how decently we do it. We've won free, and stayed free this long; now, somehow, we've got to reach our ship and get back to Earth to warn them of the danger that hides here for our planet!" He strode tensely up and down, smacking his fist into his palm. "The lever!" he exclaimed. "That lever! It's our only answer! If we could get to it.... But how can we? We couldn't break into the dome, now the Rogans are on the watch for us, with anything less than a charge of explosives. Or a tank. God, how I'd like to have an old-fashioned, fifty-ton army tank here now!" Greca exclaimed aloud as Brand's fleeting mental picture of one of Earth's unwieldy, long-discarded war tanks registered on her brain. "There is the great beast there," she said hesitantly, pointing a slim forefinger at the huge lizard that had backed into a far corner and was regarding them out of dull, savage eyes. Then she shook her head. "But that is impossible. Impossible!" * * * * * The men stared at her, with dawning realization in their minds. Then they gazed at each other. "Of course," said Brand. "Of course! Greca, you're marvelous! Wish we had a tank? Why, we've got one! A four-legged mountain of meat that ought to be able to plow through the side of that dome like a battering ram through cardboard!"