Consider Phlebas

Set amidst the devastating Idiran-Culture War, 'Consider Phlebas' plunges readers into a galaxy-spanning conflict where billions perish and entire worlds face annihilation. The Idirans, driven by fervent faith, clash with the Culture, a post-scarcity utopian civilization, over fundamental principles. At the heart of this cosmic struggle lies the fugitive Mind of a fallen Culture General, sought by both factions. Horza, a 'Changer' and a mercenary working for the Idirans, is tasked with retrieving this powerful AI from a dangerous, proscribed world known as a Planet of the Dead. Accompanied by a motley crew of unpredictable individuals and machines, Horza embarks on a perilous quest through ancient labyrinths and war-torn sectors. His journey forces him to confront the complexities of war, morality, and identity, ultimately leading him and his companions towards a destiny fraught with destruction and profound revelations about the nature of existence itself.