War on the Rolling Plains

Selyse Jackson is chosen by an alien intelligence to save the world from a force that is going to wipe humanity out of existence. It almost happened twenty years ago, when the biggest war in history went nuclear. Now, there are only small settlements scraping by, as well as millions of leftover tanks and their hungry crews. To assist her, the alien intelligence has given her a gift-a being that is both a tank and a humanoid robot, capable of feats of imagination and development. The tank's name is Ellen. Together, her and Selyse set of on a journey to save the world one city at a time.