It is a novelization of the script of the movie of the same name, written by James Dale Robinson, which itself was based on the comic by Alan Moore and Kevin O'Neill.

In late 2002, Anderson had just finished working on his novel Captain Nemo: The Fantastic History of a Dark Genius, set in a world where Jules Verne had drawn inspiration for his works from (fictional) real-life events, individuals, and technological developments.

Anderson was just beginning to work on the book that would become The Martian War, a similar premise but with H.G.

[1] Anderson turned the 120-page script into the final 288-page book by expanding scenes deleted from the final movie, expanding characterization and background information, and "wherever possible and appropriate [going] back to Moore's original graphic novel for that material and [using] what I can".

[2] Although differing somewhat from the movie script, and drawing on the original comic, Anderson still noted that "and of course another drawback is that I have to stick to the script exactly as it is, even if I might have different ideas";[1] as such, the result is much closer to the film than the comic or a third, independent story.