Astronomical calculations had soon described the mysterious hidden satellite. It was almost a twin to the moon; a very little smaller, and less than eighty thousand miles away. Its rotation was nearly similar, which made its days not quite sixteen of our earthly days. It was of approximately the weight, per cubic mile, of Earth. And there it whirled, directly in a line with the earth and the moon, moving as the moon moved so that it was ever out of sight beyond it, as a dime would be out of sight if placed in a direct line behind a penny. Zeud, the new satellite, the world beyond the moon! In their excitement at its discovery, Joyce and Wichter had left the moon--which they had found to be as dead and cold as it had been surmised to be--and returned summarily to Earth. They had replenished their supplies and their oxygen tanks, and had come back--to circle around the moon and point the sharp prow of the shell toward Zeud. The gift of the moon to Earth was a dubious one; but the gift of a possibly living planet-colony to mankind might be the solution of the overcrowded conditions of the terrestial sphere! "Speed, three thousand miles an hour," computed Wichter. "Distance to Zeud, nine hundred and eighty miles. If we don't strike a few atoms of hydrogen or something soon we're going to drill this nearest crater a little deeper!" Joyce nodded grimly. At two thousand miles from Earth there had still been enough hydrogen traces in the ether to give purchase to the explosions of their water-motor. At six hundred miles from the moon they had run into a sparse gaseous belt that had enabled them to change direction and slow their speed. They had hoped to find hydrogen at a thousand or twelve hundred miles from Zeud. "Eight hundred and thirty miles," commented Wichter, his slender, bent body tensed. "Eight hundred miles--ah!" A thrumming sound came to their ears as the shell quivered, imperceptibly almost, but unmistakeably, at the touch of some faint resistance outside in space. "We've struck it, Joyce. And it's much denser than the moon's, even as we'd hoped. There'll be life on Zeud, my boy, unless I'm vastly mistaken. You'd better look to the motor now." * * * * * Joyce went to the water-motor. This was a curious, but extremely simple affair. There was a glass box, ribbed with polished steel, about the size and shape of a cigar box, which was full of water. Leading away from this, to the bow and stern of the shell, were two small pipes. The pipes were greatly thickened for a period of three feet or so, directly under the little tank, and were braced by bed-plates so heavy as to look all out of proportion. Around the thickened parts of the pipes were coils of heavy, insulated copper wire. There were no valves nor cylinders, no revolving parts: that was all there was to the "motor."