One sunset they were all upon the lake-cooled roof, where was the glass island with its golden temple; the sun was bathing the star in liquid ruby; the emerald moon, at a point seeming nearer than ever before, came glinting its green into their skies. There were other moons, too, but only a single green one. The loud clamoring of the bird men was even more emphatic than usual. It resolved itself into words. These words were: “Farewell! farewell!” “What does this mean?” exclaimed Regan, starting to hinder them; but he returned to his seat. They had their wings and they had spread them. From all the vales, from all the hills they rose in black flocks, shadowing the palace, darkening the air. And with the thunder of many wings added to the music of their voices, they left the star, sailing till they changed into a black spot, and that soon lost to view in the distance. “A migration to that emerald moon,” said Father Renaudin. “That explains their restlessness for the past years.” “Yes, and that accounts for my half-finished cities and my slowly-built temples of commerce and art,” said Regan. “Do not grieve, Rondah,” he added. “They are gone, but more will soon blossom.” “Not so,” said Father Renaudin. “Yesterday I visited the plain and found that the southern sea had penetrated the chasm. All the bird pods sleep beneath hundreds of feet of water.” “Alas! alas! My beautiful, true friends! I did not dream that they would leave us like this!” said Rondah. “It is better so. The race of men has now possession of the star,” said Regan. “I never liked those wings, those black and breathful sheets of power. The elf men will improve into a humanity. The wingless race is almost, if not entirely, human. To us and to our children is the star, Rondah!” CHAPTER XXIV. THE MYSTERY OF THE SUN ISLAND. Of so great importance was the learning in the books that Regan and Rondah decided to explore the Sun Island and try to regain them. Father Renaudin ventured to accompany them, although until he had entirely crossed the lava bridge he was not certain that the prohibition concerning his return had been removed. True, he had once stepped upon that sacred soil, but that was in what always seemed to him like a flash of lightning-like desperation and most dangerous presumption. He found no voice nor influence commanding him to retrace his steps, and the three proceeded to make a thorough exploration. The beautiful isle lay before them, glowing like a gem, as much their own, it seemed, as any patch of earthly stubble. They had not seen it for several busy years. It was more enchanting than of yore. It even appeared larger. The rainbow cloud still hung above it, but the radiance of white, veiling light had gone with the wall. The heights of amber and garnet were clearly defined against the purplish sky of Jupiter. The amber palace stood, but no books were there.