The Doom novels are a series of three official books that were written by Dafydd ab Hugh and Brad Linaweaver and were released by Pocket Books in 1995.
The three titles, Knee-deep in the Dead, Hell on Earth, and Infernal Sky comprise a continuing narrative centering around Space Marine Flynn "Fly" Taggart and a ragtag band of human survivors. While the story is set in the Doom universe the authors take several artistic liberties. For instance, imp monsters are described in Knee-deep in the Dead as spitting flaming mucus, while the imps in Classic Doom clearly throw fireballs. The novels also introduce several other characters not suggested by the video games.