Mystery Codes From Ancient Times is Don's first book for the non-technical reader. As a Human Factors Research Engineer and Systems Analyst in the Aerospace Industry, Don Parks' role was to resolve human performance questions for vehicle design. He would seek crumbs of fact buried in a plethora of opinions and fuzzy data, applying computer simulations, laboratory tests, or systems analysis as required.

Finding opinions too often negated by fact, Don became a dedicated skeptic, questioning anything that was not rational. It was this mindset that influenced his reaction to the Cayce material, pointing him to new discoveries that would eventually lead him to write his first book.