The moss was crushed and flattened where the thing had lain, and he touched the selector of his wrist tracker and held it over the spot. The scent-cell glowed, and the tiny needle swung over to point. Fenner followed it over the ridge and down the hill on the other side. The forest began at the foot of the hill, and beyond, looming above the foliage, were the peaks of distant mountains, hazy in the faintly greenish air. Somewhere beyond those peaks the Archeological Survey was at work, and there was something comforting and neighborly in the thought. The light was always crepuscular here, and because of the color of Orpheus' sun, the sky had a green tint as of a summer pool. This green, against which the dark brown moss and lighter colors of the trees shimmered like waterweed, was extremely restful and yet alien so that in four weeks Fenner had not been able to accustom himself to it. He felt always as if he were walking in a dream, as if his limbs were weighted and languid, although in fact the purity of the air made him feel more vigorous than ever before in his forty-five years. He entered the forest which here was composed chiefly of a gray-stemmed tree, very slender and rigid with a crown of glossy red-brown leaves. The tall boles rose straight out of the moss, and there was little underbrush so that it was almost like a planted park. The needle of the tracker led him on a winding course but he was not afraid of becoming lost for if by some mischance his homing compass, which was always set for the Station, should fail, he had only to follow his own footsteps back with the tracker. * * * * * The trail led for half a mile or so through the gray trees. Now and then one of the long-tailed "birds" flashed like a shining jewel across some cleared space, the yellow-green sunlight glistening on its fur. Once in a while, a giant jointed thing, like a centipede, fluttered lazily past on wide, scaly wings. From the tree-tops came whistles and hoarse calls. He came at last to the bank of a rushing stream and the needle halted. The beast had taken to the water. Fenner decided to cast up and down the bank for a little way, in case it had come out on the same side again. He had walked only a short distance, when suddenly he had the distinct feeling that he was under observation. He glanced down at the tracker. The needle had swung over to the right. He turned slowly in that direction, at the same time cautiously raising his gun. In the corner of his eye, movement flickered. He braced himself and tapped the firing button. A halo of white light surrounded the muzzle, and there was the dull "crump!" of the discharge. He saw a flurry in the leaves of the oil-bushes that grew here and there among the trees. Leaves and bits of branches flew. A mottled gray and brown shape darted like a streak away between the trees.