A polarizing series of books that take place during the invasion of an alien ecology. They're real sci-fi, but sections of the books range from preachy to just pure fromage (and that's coming from soneone who LIKES them). Consists of four books, ranging from 1981 to 1994. Supposedly, David Gerrold is planning at least 7 at this point. The four books are A Matter For Men, A Day For Damnation, A Rage For Revenge, and A Season For Slaughter.

The books deal with concepts of worldview, communal intelligence, terraforming, and mind-altering substances. Other than that, they're just pure adventures, and probably not the best ones at that.