I glanced down at the twin charts Correy had indicated. In the center of each the red spark that represented the _Ertak_ glowed like a coal of fire; all around were the green pinpricks of light that showed the position of other bodies around us. The _Kabit_, while comparatively close, was just barely visible; her bulk was so small that it only faintly activated the super-radio reflex plates upon the ship's hull. "We're showing her a pretty pair of heels," I nodded, studying our position in both dimensions. "Arpan isn't registering yet, I see. Who's this over here; Hydrot?" "Right, sir," replied Correy. "Most useless world in the Universe, I guess. No good even for an emergency base." "She's not very valuable, certainly," I admitted. "Just a ball of water whirling through space. But she does serve one good purpose; she's a sign-post it's impossible to mistake." Idly, I picked up Hydrot in the television disk, gradually increasing the size of the image until I had her full in the field, at maximum magnification. * * * * * Hydrot was a sizable sphere, somewhat larger than Earth--my natural standard of comparison--and utterly devoid of visible land. She was, as I had said, just a ball of water, swinging along uselessly through space, although no doubt there was land of some kind under that vast, unending stretch of gray water, for various observers had reported, in times past, bursts of volcanic steam issuing from the water. Indeed, as I looked, I saw one such jet of steam, shooting into space from a spot not far from the equator of the strange world. In the television disk, it looked like a tiny wisp of white, barely visible against the gray water, but in reality it must have been a mighty roaring column of smoke and steam and erupted material. "There's life in the old girl, anyway," I commented, indicating the image in the disk. "See her spout?" We bent over the disk together, watching the white feather of steam. "First time I've ever seen that," said Correy. "I know volcanic activity has been reported before, but--look, sir! There's another--two more!" Undoubtedly, things were happening deep in the bowels of Hydrot. There were now three wisps of steam rising from the water, two of them fairly close together, the other a considerable distance away, arranged to form a very long pointed triangle, the short base of which ran close to the equator, its longer sides reaching toward one of the poles; the north pole, as we happened to view the image. The columns of steam seemed to increase in size. Certainly they mounted higher into the air. I could imagine the terrific roar of them as they blasted their way through the sullen water and hurled it in steaming spray around their bases, while huge stones fell hissing into the water on all sides. The eruption must have shaken the entire sphere; the gushing of those vomiting throats was a cataclysm of such magnitude that I could not guess its effect.