Prof. Luxo, thought killed in a previous battle with Col. Trevor and U.S. forces, returns to disrupt forces in the Atom World, sabotaging atomic experiments being conducted under Col. Trevor's leadership.; Thieves attempt to steal Dr. Pat's formula using a mechanical brain robot that's part of her lecture at the civic fair.; The mysterious fires Astra investigates turn out to be experiments performed by the People of the Flame who are seeking a new dimension in which to live, and inevitably destroy!; Celia is afraid of life and plans to marry a wash out so she won't have to worry about him straying.