When the twenty-first century drew to a close the whole human race began to revert to conditions closely approximating savagery. The low-lands were unbearable. Thick jungles of rank growth covered the ground. The air was depressing and enervating. Men could live there, but it was a sickly, fever-ridden existence. The whole population of the earth desired the high lands and as the low country became more unbearable, men forgot their two centuries of peace.Murray Leinster, called the dean of modern science-fiction, was writing amazing super-science adventures in the early twenties before there ever was such a thing. His short stories, novelettes, and serial novels have appeared in most of the major American magazines, both slick and pulp, and many have been reprinted all over the world. He has made a distinguished name for himself in the fields of adventure, historical, western, sea, and suspense stories.