It started during a winter storm on the North Eastern Seaboard which brought with it a strange green rain. Where it fell, everything withered, died, and was consumed. The residents of remote outposts in Maritime Canada escaped the worst of the early damage, but that was a blessing in disguise, for they were left to watch as first North America, then the world, was subsumed in the creeping green carpet of terror.

And that was just the beginning. New life forms began to arise from the ooze, simple organisms at first, but multiplying with ever-increasing complexity. The few human survivors are faced with a full-scale invasion... and only radical measures will guarantee the survival of the human race.