Set in the 203rd year of the Great Crusade,
Horus Rising opens as the Immortal Emperor of Mankind withdraws from the front lines and bestows command of the entire Crusade on his most trusted son, Horus Lupercal, granting him the title of Warmaster. The novel follows Horus and Garviel Loken — a Luna Wolves captain positioned to interrogate the morality of the Crusade itself — as the first subtle machinations of corruption begin to stir, with the Word Bearers Legion operating as behind-the-scenes architects of the coming rebellion. Abnett's design is to portray Horus not as a monster but as a genuine hero in the making, so that readers experience every act of loyalty and heroism as a form of loss already underway. It is Book 1 of 54 in the main Horus Heresy series, and its dramatic irony — established from the famous opening lines — gives the entire arc its central tragic engine.