"I--it was used on the moment to express the idea intended," Croft replied. "It is as though one released the reins and allowed the gnuppas to run free." Robur nodded. "Yes, I sense it. Let--her--out." Croft complied. They sped south. Without a speedometer Croft could only estimate their rate of progress, but he judged the new engine made thirty miles an hour at least. Robur was amazed. So were others after a time. The speeding car met the first of the early market throng and cleared the road of everything it met. Men, women, and live stock bolted as the undreamed engine of locomotion roared past. Their cries blended into an uproar which tore laughter from Robur's throat. Croft himself gave way to more than one smile. Swiftly they passed the area of cultivation and entered the desert road where Croft had seen the sarpelca caravan on his first Palosian day. On, on they roared along the level surface between dunes of yellow sand and across golden arid flats. The exhilaration of motion was in their veins. Head down above his wheel Croft sent the car ahead, until dashing between two dunes they came to where a second road joined that on which they ran. Robur cried out. Croft flung up his head. One swift glimpse he had of a team of purple-plumed gnuppas reared on their haunches, their forefeet pawing the air, their nostrils flaring, their eyes maddened with fright, and of a burnished carriage behind them. Then he was past, throttling the engine, seeking to bring the car to a stand. While from behind the sound of a strong man shouting, came hoarsely to his ears. CHAPTER XIII HOW NAIA FIRST SAW JASOR The car slowed down and stood still. Robur sprang to his feet. Croft turned to look back. The carriage was off the road and dashing across a level stretch of sand. How it came that Prince Lakkon's carriage was here, neither man knew. They were to only learn later that Naia, wearied of her preparations for the coming feast of betrothal, had induced her father to take her to her mountain home on the previous night, and that now she was returning in time to avoid the later heat of the Sirian day. Yet both men had recognized the purple-plumed gnuppas and the conveyance which now swayed and rocked behind their fright-maddened flight. "Lakkon's!" Croft gasped. "Aye, by Zitu," Robur gave assent. "And should Chythron fail to hold them soon, death lies in that direction at the bottom of the gorge."