The novel details the events which led up to the game and explains the origins of the SPARTAN-II supersoldiers, narrating the story of the series protagonist, the Master Chief.

The Fall of Reach was conceived after Nylund had discussed the possibility of a Halo novel with Microsoft's Franchise Development Group.

The book was well received by critics, who thought it added depth to the plot of the game, but the large number of characters was highlighted as a shortcoming.

Going on to sell over one million copies, the success of The Fall of Reach paved the way for further Xbox game novelizations, including another book in the Halo series.

Cortana, Master Chief's AI companion through much of the series, is also present as Dr. Halsey's aide in the lead-up to the Spartans' mission.

The novel opens with the civilian Dr. Catherine Halsey and Lieutenant Jacob Keyes traveling to meet John, a six-year-old boy.

Dr. Halsey reveals to Keyes that John is one of 150 children who possess rare genetic markers making them suitable for conscription into the SPARTAN-II program, a secret experiment with the aim of creating super soldiers for the UNSC to quell rebellions.

[9] Seventy-five of the children are kidnapped by operatives of the Office of Naval Intelligence and replaced by clones engineered to die of natural causes shortly thereafter.

John-117 and the rest of the children are drilled and trained by Franklin Mendez; John demonstrates leadership of his fellow Spartans, leading to his promotion to squad leader.

In 2525, the Spartans undergo a series of surgical enhancements which turn them into highly efficient super soldiers - but more than half of the original 75 conscripts are paralyzed or killed.

The Covenant land ground forces on Sigma Octanus IV, overtaking the primary population centre; Cote d'Azure, in search of an ancient artifact.

[14] Soon after, Keyes is given the command of the UNSC cruiser Pillar of Autumn for a secret mission: the Spartans are to capture one of the Covenant's religious leaders and barter a truce.

[23] Don D'Ammasa of the Science Fiction Chronicle called the book "competently written", but stated the plot was "simpleminded".

The more human Chief seen in the novel led Bungie to tone down the character model in Halo 2 to make him less an exaggerated robot and more a real person inside a suit.

[29] Stuart Beattie, the screenwriter of Pirates of the Caribbean: The Curse of the Black Pearl, wrote a spec script for a Fall of Reach movie.