In the hollow chamber of each of the twelve projectiles he placed the same message: Castaway. Mason Standish. Lieutenant-defense-engineer Earth. On unknown planet, somewhere near Sirius-Earth Route. December 28, 3020. He had no means of astronomical calculation. So he aimed the gun at twelve different points of the heavens and fired haphazardly. Chances of intelligent life ever finding those projectiles were millions to one against him. But whatever the odds, he must miss no opportunity. Next he made a thorough survey of the wrecked liner, carrying all usable objects to the forecastle, which swiftly took on the appearance of a storage room. As these articles began to grow in number, satisfaction and pride of ownership gripped him. It was in the midst of these labors that he was suddenly struck with an idea. Why not construct a space ship from the wrecked parts of the liner? He had six atomic motors, and surely from their wreckage he could salvage enough to build one of half the trajectory power. And with a smaller ship, he might be able to find his way back to Earth. Standish smoked a pipe over this. When morning came, he began the herculean task of dismantling the motors. Day after day he struggled with the cumbersome machinery. When this stage of the work was finally completed, he was startled to discover that six weeks of Earth time had slipped by. He then found in the machinists' quarters an electrolic saw. The tool was dull, but he managed to cut free a dozen girders for the framework of his craft. To his dismay he found them too heavy to move even with block and tackle. There was no alternative but to cut them into sections and weld them together, hoping they would stand the strain. That night the first warning of trouble came. Absently Standish had noticed a chill in the air, a more oblique slant to the twin suns. Suddenly from the jungle beyond the ravine came a low rumbling. The Earthman switched on a searchlight he had fastened on top of the forecastle. The white glare fastened itself on the wall of trees, revealed five figures advancing directly into the light. On all fours they came, huge beasts with long tapered bodies covered with heavy white fur. Their heads resembled the saber-toothed tigers of Earth's Upper Miocene. A dozen appeared before Standish understood.