Making a quick check of their oxygen supply, Tom patted Astro on the back and started forward. "It's O.K. We've got another four hours left. Come on!"
They moved toward the trap door slowly.
"I still wish I had a ray gun," whispered Tom.
"As long as I can use these"—Astro balled his hamlike hands into fists—"we're O.K."
When they reached the trap door, Tom got down on his knees and felt around for the opening. He found a small ring bolt, motioned to Astro to step back, and pulled. The trap door swung back easily and a shaft of white light gleamed in his face. The young cadet leaned down and looked through the opening. What he saw made him gasp.
"What is it?" demanded Astro.
Tom got down on his knees and felt around for an opening
Tom motioned for him to get down and look. The big cadet dropped lightly to his knees to peer through the opening. "By the moons of Jupiter," he exclaimed, "it's a—a mining shaft!"