"Excession" is a science fiction novel by Iain M. Banks, part of his renowned Culture series. The story revolves around a mysterious object known as the Excession, which appears out of nowhere and defies the known laws of physics. This enigmatic phenomenon captures the attention of the Culture, a highly advanced society of humanoids and artificial intelligences, leading to various factions vying for control and understanding of the Excession. The narrative intricately weaves together multiple perspectives, showcasing the complexities and power dynamics within the Culture and its interaction with other civilizations.
Central to the plot is the involvement of the Culture's advanced AI ships, who each have their own agendas and personalities. Their discussions and interactions reveal philosophical questions about intelligence, morality, and the nature of existence, as they strive to comprehend the implications of the Excession. The story is marked by witty dialogue and intricate world-building, as Banks explores themes of communication, power, and the limits of understanding in the face of the unknown.