Robur was inseparable during those days from Croft. He viewed the monster devices with unbounded enthusiasm and amaze, vowing them the marvel of their age, repeating over and over again his own conception of the consternation they must cause in Zollarian minds when, without warning, they appeared and hung above Berla's walls. Gaya drove down at his solicitation on one occasion and gazed at the hugely bulking shapes out of widening brown eyes. Word came again from Zitra that the Tamarizian delegation had gone north. "Let them go," Croft cried to Robur. "Ere long shall Jason follow." "Aye, by Zitu," the Aphurian replied, casting his eyes toward the glistening gas-bags, beneath which the swarming workmen toiled. * * * * * Came a day when the last rivet was driven home, the last nut screwed into place, when Croft distributed largess to the workmen and a vast roar of human voices filled all the places where his latest creation had been given birth. Croft stood with Robur and viewed them--the mighty engines for the deliverance of his hostages to fate. His heart leaped. "With the sun," he said, turning to his companion, "let Himyra see them. We make a test." "I and thou," Robur returned, flashing his even teeth. "Dost remember the dawn you mounted the skies in the first airplane, Jason--and, returning, found Naia waiting to dare the venture with you? Now, by Zitu, Robur goes to try these blimps himself." Croft nodded. His hand crept out and closed on the other man's. Well he remembered the day his words recalled. His return from the trial flight in the plane to find Naia waiting beside the hangar in her russet leather dress, and how as they rose between the Sirian sun and Himyra, she had lifted her voice and sung in a pure abandonment of emotion. Deep in his heart he vowed that these monsters of his construction should bring her back to Himyra--give her the opportunity to sing again. Yet, all he said to Robur was, "Aye, Rob, if you wish." Robur's muscles gripped down upon his fingers. "And not only to the testing, friend of Aphur, but even to Berla itself." "Berla." Croft loosened his hand to lay it on Robur's shoulder, look into the son of Jadgor's eager face. "It is not in my heart, Rob, to refuse you anything in this." Dawn came and Himyra gasped--gasped and stood with heads back-tilted, staring upward at a mighty oblong bag that swung in majestic fashion high above the walls. It hung there like a monstrous bubble, glinting as the rays of Sirius struck upon it--drifting slowly as it seemed before the winds of morning. And yet--even as they watched it, turning and moving against the wind in steady fashion--silently--without seeming reason, too high above the red, red city of Aphur, for the ears of her people to sense how its moturs roared.