From the Introduction:
Five hundred years ago Rhand was a quiet, pastoral world at the edge of a growing interstellar community. Specializing in tourism and agriculture. Rhand was a world of open spaces, a world with little industry and few cities. It was a world devoted to peace and prosperity, not a perfect planet but one with promise.
Five hundred years ago the Spectrals came. Faceless, jet-black humanoids having a group mind, they launched a full-scale invasion of human space. Desperate warfare broke out on dozens of worlds.