on Earth and wiser and more understanding. In the long run no human woman could resist him. Had they not already captured and studied dozens of human women? They had needed to do that for a quite different reason, a reason not associated with lovemaking at all. They had held themselves in restraint, because they had not been so long cut off from the women of their own race that the torment and frustration had become unendurable. Studying the women of Earth had been part of the master plan, the Great Plan for Earth conquest. Nothing must be allowed to interfere with that plan even now. But now there was another need—compulsive, overwhelming. For every Martian a mate must be found—a woman tender and yielding. For every Martian. Tragor straightened in sudden alertness, his eyes on a stretch of open countryside a few hundred feet in front of the steadily advancing ship. Between a winding brook and a small, tree-shadowed grove eight or ten tiny human figures were moving slowly about or sitting in pairs on the grass. He had seen such groups before and the sight did not surprise him. They were hikers, relaxing after a strenuous tramp over the green-yellow hills, and enjoying one another's company by a cool stream in the shadow of whispering boughs. They had unwrapped packages of food and spread a white tablecloth on the grass and at the edge of the stream a girl with gold-red hair was filling a pail with water. He could see the girl clearly now, her slender supple form bent seductively above the pale, sky-mirroring water. There were other girls in the group but even at a distance they seemed far less attractive. Two were very stout and one was a gaunt, big-boned woman with almost mannish features and no roundness where Tragor looked for roundness with anticipatory delight. He saw now that the group consisted of eight people, and that four of them were men. The men could be destroyed without difficulty and presented no problem. But he studied them carefully nevertheless. He studied their physiques for muscular sturdiness and their faces, as the ship drew rapidly nearer, for qualities which might prove troublesome in a struggle, however heavily the odds were weighted against them: resolution, defiance, firmness of mind and will. He knew that a few men would fight to the death, counting their own lives of no importance, if a monster threatened a woman dear to them. Tragor recoiled a little at the thought, cursing