Greg Walker (with uncredited contributions from Jeffrey Bell and Steven Maeda). Director: Barry K. Thomas.

The "fire under skin" effect was a significant production feat using green screen technology to make Jeb Dukes appear to be a living container for a raging fire.

"Empedocles" serves as a bridge between the classic Mulder/Scully dynamic and the new Doggett/Reyes era. It emphasizes the philosophical divide between Doggett’s rigid factualism and Reyes’ more spiritual, intuitive approach to the paranormal. "The X-Files" Empedocles (TV Episode 2001) - IMDb

The story follows , a man who begins experiencing horrifying hallucinations of fire burning beneath his skin after witnessing a fiery car crash. Driven by this perceived "pure evil," he goes on a killing spree.