Harlan Williams is an elderly janitor who is caught in an explosion in the laboratory where he works and suffers strange side effects. An investigation lead by laboratory security head Terry Spann suspects that the explosion was caused the negligence of Dr. Richard Toddhunter. Agents from "the Shop", however, cover up the crime so the doctor can continue his research.
Harlan Williams's and his wife Gina begins to notice that he is getting younger and that old scars are healing as a result of his accident. He returns to work and dyes his hair white in an effort to conceal what is happening to him. This does not stop Shop agent Jude Andrews from becoming suspicious.
When people linked to Harlan Williams begin to die, Terry Spann grows suspicious of the Shop. She decides to protect Harlan and his wife and manages to win their trust despite some initial hesitation. She takes them on the road but Shop agent Jude Andrews is on their tail convinced that Harlan is the key to the fountain of youth.
Harlan, Gina, and Terry hide temporarily in the country and discuss their options. Meanwhile Jude Andrews continues his pursuit and consolidates his position at the research center while Dr. Toddhunter works to recreate his research despite showing serious signs of mental illness.
Jude Andrews continues his hunt for Harlan, Terry, and Gina. The three fugitives first avoid local police and then decide to split up in order to be less conspicuous. Before they can meet back up Harlan begins to manifest strange new reality influencing powers.
Gina takes Nancy to her blind daughter Francie's house. Meanwhile Harlan is traveling more slowly. His eyes begin to glow green at times and he uncontrollably causes earthquakes. Harlan eventually reaches Francie's house with Jude Andrews close in pursuit. With the help of Gen. Crewes, they manage to escape.
Harlan, Terry, Gina, and General Crewes head to a safe house lead by one of Francie's former anti-establishment hippie friends. After getting a tip off from an informant, Jude Andrews closes in on their position and forces an armed showdown at the safe house.