"We ran out of fuel here on Lomihi," he finished, "with the vanished surface waters of Mars less than four miles beneath us."
Rolf followed the direction of the other's pale blue eyes. Overhead now hung the bottom of the cavern. An almost circular island of pale yellow lifted above the restless dark waters of a vast sea. Rolf realized with a wrench of sudden fear that they actually hung head downward like flies walking across a ceiling.
"There," roared Tanner's voice, "is one of the seas of Mars."
"One," repeated Rolf slowly. "You mean there are more?"
"Dozens of them," the older man's voice throbbed with helpless rage. "Enough to make the face of Mars green again. Cavern after cavern lies beyond this first one, their floors flooded with water."
Rolf felt new strength pump into his tired bruised muscles. Here lay the salvation of Earth's thirsting colonies almost within reach. Once he could lead the scientists of North Mars to this treasure trove of water....
"Mark!" The girl's voice was tense. Rolf felt her arm tug at his sleeve and he dropped beside her in the shelter of a clump of coarse-leaved gray bushes. "The Furry Women attack!"
A hundred paces away Rolf made the dark shapes of armed warriors as they filed downward from the Barrier into the blackened desolation of the desert half of Lomihi.
"Enemies?" he whispered to Mark Tanner hoarsely.