The Ragged World

In the early years of the twenty-first century, Earth teetered on the brink of ecological destruction. Then the alien Hefn came, determined to save the dying Earth — and to the Hefn, the ends always justified the means. Humans were given nine years to correct their mistakes — alone, with no recourse to the Hefn's advanced technology. If by then the Earth's ecology had not stabilized, the Hefn would solve the problem for good . . . by eliminating humans entirely.

But slowly, against their wil...