Cargo pilot Scott Nash has two passengers bound for Washington, D.C. Dr. Linda McCoy is hurrying to monitor incoming Hurricane Sigrid. Vivian Henry is delivering what she believes is the prototype of a thermonuclear device to the Pentagon. The nuclear warhead, code-named Medusa, is not only capable of mass destruction, but also of creating an electromagnetic charge so powerful it would destroy every electrical device and computer in its path. Medusa is the work of Vivian's ex-husband, embittered scientist Rogers Henry, whose relationship with Vivian and the Pentagon, ended abruptly. Terminally ill, Henry's last wish is that Vivian deliver his work to Washington. But Vivian realizes that she has been duped when Medusa begins ticking and a robot-like voice from within states that the fully armed nuclear warhead will detonate within hours. Medusa is Rogers Henry's ultimate revenge against the wife and the government he feels spurned him.