The novel “Consider Phlebas” by Iain M. Banks was published for the first time in 1987. It’s part of the Culture series.
During the Idiran–Culture War, one of the Culture’s starships is destroyed during an Idiran attack but its Mind, the artificial intelligence that controlled it, survives. With a desperate maneuver, the Mind manages to hide on the planet Schar, under the protection of the Dra’Azon, entities so powerful that neither of the two contenders wants to provoke their anger.
Bora Horza Gobuchu is a Changer on a mission for the Idirans thanks to her ability to change his appearance. The intervention of Perosteck Balveda, a Culture agent, causes Horza’s mission to fail and the Changer must be rescued by the Idirans. An attack by the Culture puts him in danger again, and this time he’s rescued by a Free Company of mercenaries’ starship. Horza is forced to fight for his life and to continue his mission by reaching the planet Schar.