Someday this would have to be investigated. If he ever returned to Earth, this would have to be explored. But now--were these unknowns dangerous to him? He asked Korree, who shrugged. In his halting fashion he conveyed to the Earthling that if the Glassies of the upper crust left those lower down alone, they were not bothered. The implication however was that Korree's people were only too willing to stay out of the way of the powerful underlords. After several more caverns--the trip had already taken over a week--including one marvelous one in which several flaming gas jets made amazing patterns in an otherwise lightless world, Korree finally led the way into a large lighted cavern many miles wide, stopped and announced, "Korree home." Robin looked around, adjusted his pack and called to Cheeky to return. The monkey, which had scampered on ahead, obediently dashed back and to safety on the pack. This was an important moment to Robin. He mustered his plans, and stepped out after Korree who had started out again holding his spear high in the air in some sort of native signal. For a short while they walked without seeing anyone. They were in a forest of ball-trees when suddenly they found themselves quietly surrounded by Glassies. Evidently they had been trailed since entering the cavern and at a sufficient distance from the tunnel mouth the Glassies had popped out of concealment. There were about twenty or so, all armed with the diamond spears and they effectively encircled the travelers. Korree had apparently expected this, for he showed no surprise, but Robin stopped short and Cheeky started jumping up and down on the huge pack and shrieking at the pack of beings. It was odd seeing a mass of Glassies. Robin could see that they differed from each other as individuals. Some were larger, some smaller, and the shadings within their bodies gave rather clear evidence of fatness, of recent eating, and such. Like Korree they wore no garments at all. One of the Glassies said something sharply to Korree, who answered promptly. The spokesman had a black circle painted on his chest--this was obviously a symbol of some sort of tribal authority. Robin stepped forward, walked up to this Glassie, who promptly withdrew, uneasy in the presence of this unknown. From his pocket Robin took his pack of matches, the one that had been with him all the way from Earth. There were still three matches left, saved for just some occasion as this, carefully conserved by the use of Robin's flint and steel. Robin walked up to a small ball-tree nearby, held the match aloft, then struck it, and rapidly held it to the stalklike trunk. After a second the plant caught fire and was a blazing mass. While the Glassies were gazing in amazement at this unexpected display, Robin drew in his breath, set his pack down, and gave a leap straight upward with all his strength.