The two Europans were delighted with the appointments and mechanisms of the little vessel from Mars. They investigated every nook and cranny of its interior during the journey and were voluble in their praise of its inventor and builder. Neither had ever set foot in a space-flier and each was seized with a longing to explore space with these two strangers from the inner planets. They would make a couple of good vagabonds along with Mado and himself, Carr thought as they expressed their feelings. But there was more serious business at hand. They were nearing Ganymede. "Where'll we land, Detis?" Mado called from the control cabin. "Vlor-urdin. That is their chief city. I'll guide you to the location." * * * * * They took up their places at the ports and scanned the surface of the satellite as Mado dropped the ship into its atmosphere. A far different scene was presented than on Europa. The land was seamed and scarred, the colors of the foliage somber. Grays and browns predominated and the jungles seemed impenetrable. A river swung into view and its waters were black as the deepest night, its flow sluggish. A rank mist hung over the surface. "The river of Charis!" exclaimed Detis. "Follow it, Mado. No, the other direction. There! It leads directly to Vlor-urdin." By good chance they had entered the atmosphere at a point not far from their destination. In less than an hour by the _Nomad's_ chronometer the towers of Vlor-urdin were sighted. It was a larger city than Pala-dar and of vastly different appearance. A hollow square of squat buildings enclosed the vast workshops and storage space of the fleet of war vessels. Their huge spherical bulks rose from their cradles in tier after tier that stretched as far as the eye could reach when the _Nomad_ had dropped to a level but slightly above the tips of the highest spires. The spires were everywhere, decorative towers at the corners of the squat buildings. Everything was black, the vessels of the fleet, the squat buildings and the spires of Vlor-urdin. Death was in the air. Rank vapor drifted in through the opened ports. There was silence in the city below them and silence in the _Nomad_. Ora shuddered and drew closer to him. Carr was aware of her nearness and a lump rose in his throat. A horrible fear assailed him. Fear for the safety of the dainty Europan at his side. He found her hand; covered it protectingly with his own. CHAPTER VII _Rapaju_ Detis was setting up and adjusting the complicated mechanisms of his little black case. A dozen vacuum tubes lighted, and a murmur of throbbing energy came from a helix of shining metallic ribbon that topped the whole. Flexible cables led to a cap-like contrivance which Detis placed on his head. He frowned in concentration. "The psycho-ray apparatus." Ora explained. "He's sending a message to the city."