"Boy, is he blasting his jets!" commented Roger.
"Yeah," grunted Astro. "He should have to dig this blasted hole!"
"Well, this is where it's got to go. If the ground is hard, then it's our tough luck," said Roger. "If we stick it anywhere else, it might mess up the whole operation."
Astro nodded and continued to dig. He held a small spade and jabbed at the ground. "How much—time—have we got left?" he gasped.
"Twenty minutes," replied Roger. "You'd better hurry."
"Finished now," said Astro. "Get the reactor unit over here and set the fuse."
Roger picked up the heavy lead box and placed it gently inside the hole.
"Remember," Astro cautioned, "set the fuse for two hours."
"No, you're wrong," replied Roger. "I've set the fuses each time, subtracting the amount of time since we left the Polaris. I set this one for twenty minutes."
"You're wrong, Roger," said Astro. "It's maximum time is two hours."