Excession

"Excession" is a science fiction novel by Iain M. Banks, part of his Culture series. It explores themes of advanced artificial intelligences, space diplomacy, and the limits of understanding between highly capable civilizations. The story centers around a mysterious, powerful alien artifact called an "Excession," which challenges the Culture’s leadership and prompts complex political and technological conflicts. The novel delves into issues of trust, power, and the nature of intelligence—both artificial and organic—questioning how advanced beings interact and the moral dilemmas they face when confronting the unknown.