The city of Ilen-dar was left far behind. Patches of jungle flashed by; other cities. And always the endless rows of blue-white lights. There was neither night nor day in the sealed-in world; only the artificial suns that never set. Continuous subjection to the ultra-violet and visible rays of the vast lighting system was necessary to the growth and reproduction of the plant life that was so essential in keeping the atmosphere breathable. Tommy had forgotten everything save his interest in the mechanism of the car. He and Dantus were fast friends already. Chin in hand and eyes avoiding the pain of mourning in Tiedus' fixed gaze, Carson lost himself in gloomy meditation. As he thought back over the events of the past few days he could scarcely believe they had actually occurred or that he was sitting here in a mystery car, speeding through the rank atmosphere of an enclosed world a half billion miles from his own. Home seemed incredibly remote and desirable just then, and the future dark and forbidding. CHAPTER V _The Tritu Anu_ Before the car came to a stop Tiedus rummaged in a locker and stretched forth his hands as if carrying something delicate and fragile. "It will be necessary for you to put this on," he said: "it will be unsafe otherwise." Blaine stared, mystified. Was this Rulan kidding him? "Put what on?" he asked. "A thousand pardons. I had forgotten that you do not know. I hold in my hands a cloak, an invisible thing that will hide you from the guards and from the Zara's crystal. Another secret of my father's. Dantor developed it for him only recently." Blaine felt the texture of the stuff then; crumpled it in his fingers as its gossamer-like weight dropped in loose folds around his body. But there was nothing there: to the eyes. It simply did not exist except to the touch, and he felt no different with it on than he had before. "Where's Tommy?" he asked suddenly, seeing that Dantus now sat alone at the controls. Tiedus laughed. "He has been covered in the same manner," he said, "and is safely hidden from sight as are you." Incredulous, disbelieving, Blaine called out to his friend in a tremulous voice. And Tom Farley's awed response reassured him. "Keep close to me," Tiedus told him. The car had stopped and he directed them into the basket of the lift. The two Earth men collided violently and, clinging to each other in their ghastly invisibility, laughed crazily for a moment. As far as any observers might know there were only the two Rulans in the basket. * * * * * Blaine fingered Pegrani's ray pistol when the cable lowered them swiftly to the roof of a huge steel cylinder that rose, a solitary and unlovely structure, in the midst of the jungle a thousand miles from Ilen-dar. The indicator informed him that seven energy charges still remained in the storage chamber of the little weapon. Its possession brought him a measure of confidence.