"Yeah," said Crag, indecisively. The rift was about twenty feet wide, its bottom lost in black shadows.
Larkwell studied the chasm carefully. "Might be just the rill we need for an airlock. If it's not too deep," he added. He picked up a boulder and dropped it over the edge, waiting expectantly. Crag chuckled. The construction man had forgotten that sound couldn't be transmitted through a vacuum. Larkwell caught the laugh in his earphones and smiled weakly.
He said sheepishly, "Something else to learn."
"We've plenty to learn." Crag looked both ways. To the right the chasm seemed to narrow and, although he wasn't sure, end.
"Let's try it," he suggested. Larkwell nodded agreement. They trudged along the edge of the fissure, walking slowly to conserve their energy. The plain became more uneven. Small outcroppings of black glassy rock punctured the ash, becoming more numerous as they progressed. Occasional saw-toothed needles pierced the sky. Several times they stopped and looked back at the Aztec. It was a black cylinder, smaller yet seemingly close.
Crag's guess was right. The chasm narrowed abruptly and terminated at the base of a small knoll. Both rockets were now hidden by intervening rocks. He hesitated before striking out, keeping Backbone Ridge to his right. The ground became progressively more uneven. They trudged onward for over a mile before he caught sight of the Aztec again. He paused, with the feeling something was wrong. Larkwell put it into words.
"Lost."
"Not lost, but off course." Crag took a moment to get his bearings and then struck out again thinking their oxygen supply couldn't stand many of these mistakes.
"How you doing, Skipper?"
Crag gave a start before remembering that Prochaska and Nagel were cut into their intercom.