"How do they propel themselves?" he demanded.

"No one knows," Harkness told him. "That luminosity in action means something—some conversion of energy, electrical, perhaps, to carry them on lines of force of which we know nothing as yet. That's a guess—but they do it. You and I can swear to that."

Chet was pondering deeply. "High-level lanes are closed," he said, "and we are blockaded like the rest of the world. It looks as if our space flights were off. And the Dark Moon trip! We could have made it, too."


f there was a questioning note in those last remarks it was answered promptly.

"No!" said Harkness with explosive emphasis. "They won't stop me." He struck one clenched fist upon the gleaming hull beside him.

"This is all I've got. And I won't have this if that gang of Schwartzmann's gets its hands upon it. The best I could expect would be a long-drawn fight in the courts, and I can't afford it. I am going up. We've got something good here; we know it's good. And we'll prove it to the world by reaching the Dark Moon."

Another filmy, fibrous mass that had been torn from one of the monsters of the heights slid from above to make a splotch of colorless matter upon the floor.

Harkness stared at it. The firm line of his lips set more firmly still, but his eyes had another expression as he glanced at Chet. He would go alone if he must; no barricade of unearthly beasts could hold him from the great adventure. But Chet?—he must not lead Chet to his death.