His pistol held ready, he moved quietly on down the ravine until the old water course made an abrupt hairpin turn. Instead of following around the sharp bend, Jon Karyl moved straight ahead through the overhanging bushes until he came to a dense thicket. Dropping to his hands and knees he worked his way under the edge of the thicket into a hollowed-out space in the center. * * * * * There, just ahead of him, was the lock leading into the service station. Slipping a key out of a leg pouch on the space suit, he jabbed it into the center of the lock, opening the lever housing. He pulled strongly on the lever. With a hiss of escaping air, the lock swung open. Jon Karyl darted inside, the door closing softly behind. At the end of the long tunnel he stepped to the televisor which was fixed on the area surrounding the station. Jon Karyl saw none of the steel-blue creatures. But he saw their ship. It squatted like a smashed-down kid's top, its lock shut tight. He tuned the televisor to its widest range and finally spotted one of the Steel-Blues. He was looking into the stationary rocket engine. As Karyl watched, a second Steel-Blue came crawling out of the ship. The two Steel-Blues moved toward the center of the televisor range. They're coming toward the station, Karyl thought grimly. Karyl examined the two creatures. They were of the steel-blue color from the crown of their egg-shaped heads to the tips of their walking appendages. They were about the height of Karyl--six feet. But where he tapered from broad shoulders to flat hips, they were straight up and down. They had no legs, just appendages, many-jointed that stretched and shrank independent of the other, but keeping the cylindrical body with its four pairs of tentacles on a level balance. Where their eyes would have been was an elliptical-shaped lens, covering half the egg-head, with its converging ends curving around the sides of the head. Robots! Jon gauged immediately. But where were their masters? The Steel-Blues moved out of the range of the televisor. A minute later Jon heard a pounding from the station upstairs. He chuckled. They were like the wolf of pre-atomic days who huffed and puffed to blow the house down. The outer shell of the station was formed from stelrylite, the toughest metal in the solar system. With the self-sealing lock of the same resistant material, a mere pounding was nothing. Jon thought he'd have a look-see anyway. He went up the steel ladder leading to the station's power plant and the televisor that could look into every room within the station. He heaved a slight sigh when he reached the power room, for right at his hand were weapons to blast the ship from the asteroid. Jon adjusted one televisor to take in the lock to the station. His teeth suddenly clamped down on his lower lip.