Misunderstandings about the nature and content of National Fire Code© NFPA 921 - Guide for Fire and Explosion Investigations abound in the fire investigation industry. These “Myths and Mysteries” tend to depreciate the value of the document, especially among those who need its guidance the most. This is caused by failures to understand and appreciate the nature of the NFPA consensus code promulgation system, the history of the fire investigation profession, the nature and history of NFPA 921 itself; and even semantics. This presentation is designed to expose and explain what the ill-informed see as the “myths and mysteries” and perceived shortcomings of this seminal document. One of the three, still serving, original Technical Committee on Fire Investigations members discusses the most common and controversial misunderstandings and misconceptions about NFPA 921.