35 years ago, Earth was invaded by what seemed at the time an invincible army of aliens. Were it not for the aliens' susceptibility to ordinary bacteria, the invasion would have been successful, the common cold accomplished what atomic bombs had failed to do. The aliens were stopped, but not defeated. The aliens did not die. Their complex molecular structure merely retreated into a form of suspended animation, imprisoning them in a state of involuntary hibernation. Revived by accidental exposure to radioactive waste, the aliens have resumed their deadly mission: to rid the Earth of all human life and prepare it for alien colonization. Four intrepid people find themselves thrown together by this new alien threat: Dr. Harrison Blackwood, an eccentric astrophysicist recruited to lead the scientific assault against the aliens; Dr. Suzanne McCullough, a brilliant microbiologist and single mother whose serious demeanor contrasts with Blackwood's non-conformity; Norton Drake, a computer genius who operates from a voice-controlled wheelchair; and Lt. Col. Paul Ironhorse, a Cherokee Indian and West Point graduate with an extensive knowledge of weapons and tactics. Together they face an unspeakable challenge: to defeat this ruthless enemy from space or forfeit the future of mankind.
The television series, which debut with a two-hour premiere episode, picks up the story 35 years later, in 1988. Harrison Blackwood, adopted as a child by Dr. Forrester after his parents were killed by the aliens, has grown to be a gifted astrophysicist. When it is discovered that the aliens have "resurrected" and resumed their deadly mission, Dr. Blackwood becomes one of the few people in the world who knows the truth. It is now left up to him and his team to devise a means of destroying the aliens before the aliens can wipe out mankind. Produced by Triumph Entertainment Corporation of Canada in association with Ten-Four Productions and is distributed by Paramount Domestic Television.