Flynn Taggart, or "Fly" for short is the protagonist of the original Doom novels and is based on the protagonist of Doom I and II (Doom Marine/aka B.J. Blazkowicz III), though his history deviated from the game stories midway. By the end of the series there are two Flynn Taggarts: the original and a copy of his mind in a simulator forced to replay the events of Doom I and II over and over again.