Krai approached warily. He realized that these people were still very primitive, had not even begun to walk on the ground. Up to now he had exercised overmuch caution because he hadn't known what to expect, but now he knew there was nothing to fear. Detaching his pressure projector from the equipment secured to his back, Krai advanced on the alert. His job was by no means an easy one, despite the fact that everything seemed to be working in with his plans. If he were discovered, disaster could still wreck those selfsame plans. He paused. Through the concealing foliage he looked out upon a small clearing. In the trees surrounding this were the houses of the arboreal community and, singly and in groups, chattering gibberish to each other, its inhabitants. * * * * * They were outlandish-looking beings to Krai, just as he would have been to them. Nearly twice as tall as he and powerful with the strength of the brute. Few of them wore any covering, but the plentiful hair on their bodies seemed to be ample covering of itself. Communication was carried on with a combination of grunts and gestures and as far as Krai could make out the articulate part was very limited in meaning; almost incomprehensible to an intelligent mind. So far they hadn't detected the presence of another, but the alien knew he must not tarry. Moving into the shelter of two thick tree boles, Krai brought his pressure projector into play. The large communal house suddenly appeared to smash in upon itself, as though crushed by a giant hand. Screams of agony issued from the splintered walls as it crashed to earth. The tree-dwellers stopped everything they were doing to gaze in stupefaction at this prodigy. But before they could voice their amazement, another structure shattered under the emanation from the pressure projector. As the ray was invisible, it appeared to the thunder-struck denizens as though some angry unseen demon were venting his displeasure upon the village. Instinctively, a large crowd banded together for mutual protection. This was what Krai had been waiting for. They were annihilated. Those who still lived fled. But Krai's implacable destruction sought them out and none got far before they were caught. When the alien emerged from his place of concealment, all that remained of the village was a few heaps of shattered pulp. He had done his job well. * * * * * As Krai retraced his steps through the forest, his thoughts were far away. They reached back across the millions of miles of emptiness he had traversed to come here, back to his own people. They had been doomed; extinction facing them from over-population and lack of water. Mars was nearing the end, and its mighty race seemed about to share the fate of their planet, when a ray of hope came to them. The long-forgotten secret of inter-planetary travel had been rediscovered. It was as a straw to the dying man.